ip address assignment best practices

Understanding IP Address Assignment: A Complete Guide

Introduction

In today's interconnected world, where almost every aspect of our lives relies on the internet, understanding IP address assignment is crucial for ensuring online security and efficient network management. An IP address serves as a unique identifier for devices connected to a network, allowing them to communicate with each other and access the vast resources available on the internet. Whether you're a technical professional, a network administrator, or simply an internet user, having a solid grasp of how IP addresses are assigned within the same network can greatly enhance your ability to troubleshoot connectivity issues and protect your data.

The Basics of IP Addresses

Before delving into the intricacies of IP address assignment in the same network, it's important to have a basic understanding of what an IP address is. In simple terms, an IP address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It consists of four sets of numbers separated by periods (e.g., 192.168.0.1) and can be either IPv4 or IPv6 format.

IP Address Allocation Methods

There are several methods used for allocating IP addresses within a network. One commonly used method is Dynamic Host Configuration Protocol (DHCP). DHCP allows devices to obtain an IP address automatically from a central server, simplifying the process of managing large networks. Another method is static IP address assignment, where an administrator manually assigns specific addresses to devices within the network. This method provides more control but requires careful planning and documentation.

Considerations for Efficient IP Address Allocation

Efficient allocation of IP addresses is essential for optimizing network performance and avoiding conflicts. When assigning IP addresses, administrators need to consider factors such as subnetting, addressing schemes, and future scalability requirements. By carefully planning the allocation process and implementing best practices such as using private IP ranges and avoiding overlapping subnets, administrators can ensure smooth operation of their networks without running out of available addresses.

IP Address Assignment in the Same Network

When two routers are connected within the same network, they need to obtain unique IP addresses to communicate effectively. This can be achieved through various methods, such as using different subnets or configuring one router as a DHCP server and the other as a client. Understanding how IP address assignment works in this scenario is crucial for maintaining proper network functionality and avoiding conflicts.

Basics of IP Addresses

IP addresses are a fundamental aspect of computer networking that allows devices to communicate with each other over the internet. An IP address, short for Internet Protocol address, is a unique numerical label assigned to each device connected to a network. It serves as an identifier for both the source and destination of data packets transmitted across the network.

The structure of an IP address consists of four sets of numbers separated by periods (e.g., 192.168.0.1). Each set can range from 0 to 255, resulting in a total of approximately 4.3 billion possible unique combinations for IPv4 addresses. However, with the increasing number of devices connected to the internet, IPv6 addresses were introduced to provide a significantly larger pool of available addresses.

IPv4 addresses are still predominantly used today and are divided into different classes based on their range and purpose. Class A addresses have the first octet reserved for network identification, allowing for a large number of hosts within each network. Class B addresses reserve the first two octets for network identification and provide a balance between network size and number of hosts per network. Class C addresses allocate the first three octets for network identification and are commonly used in small networks.

With the depletion of available IPv4 addresses, IPv6 was developed to overcome this limitation by utilizing 128-bit addressing scheme, providing an enormous pool of potential IP addresses - approximately 3.4 x 10^38 unique combinations.

IPv6 addresses are represented in hexadecimal format separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). The longer length allows for more efficient routing and eliminates the need for Network Address Translation (NAT) due to its vast address space.

Understanding these basics is essential when it comes to assigning IP addresses in a network. Network administrators must consider various factors such as the number of devices, network topology, and security requirements when deciding on the IP address allocation method.

In the next section, we will explore different methods of IP address assignment, including Dynamic Host Configuration Protocol (DHCP) and static IP address assignment. These methods play a crucial role in efficiently managing IP addresses within a network and ensuring seamless communication between devices.

Methods of IP Address Assignment

IP address assignment is a crucial aspect of network management and plays a vital role in ensuring seamless connectivity and efficient data transfer. There are primarily two methods of assigning IP addresses in a network: dynamic IP address assignment using the Dynamic Host Configuration Protocol (DHCP) and static IP address assignment.

Dynamic IP Address Assignment using DHCP

Dynamic IP address assignment is the most commonly used method in modern networks. It involves the use of DHCP servers, which dynamically allocate IP addresses to devices on the network. When a device connects to the network, it sends a DHCP request to the DHCP server, which responds by assigning an available IP address from its pool.

One of the key benefits of dynamic IP address assignment is its simplicity and scalability. With dynamic allocation, network administrators don't have to manually configure each device's IP address. Instead, they can rely on the DHCP server to handle this task automatically. This significantly reduces administrative overhead and makes it easier to manage large networks with numerous devices.

Another advantage of dynamic allocation is that it allows for efficient utilization of available IP addresses. Since addresses are assigned on-demand, there is no wastage of unused addresses. This is particularly beneficial in scenarios where devices frequently connect and disconnect from the network, such as in public Wi-Fi hotspots or corporate environments with a high turnover rate.

However, dynamic allocation does have some drawbacks as well. One potential issue is that devices may receive different IP addresses each time they connect to the network. While this might not be an issue for most users, it can cause problems for certain applications or services that rely on consistent addressing.

Additionally, dynamic allocation introduces a dependency on the DHCP server. If the server goes down or becomes unreachable, devices will not be able to obtain an IP address and will be unable to connect to the network. To mitigate this risk, redundant DHCP servers can be deployed for high availability.

Static IP Address Assignment

Static IP address assignment involves manually configuring each device's IP address within the network. Unlike dynamic allocation, where addresses are assigned on-demand, static assignment requires administrators to assign a specific IP address to each device.

One of the main advantages of static IP address assignment is stability. Since devices have fixed addresses, there is no risk of them receiving different addresses each time they connect to the network. This can be beneficial for applications or services that require consistent addressing, such as servers hosting websites or databases.

Static assignment also provides greater control over network resources. Administrators can allocate specific IP addresses to devices based on their requirements or security considerations. For example, critical servers or network infrastructure devices can be assigned static addresses to ensure their availability and ease of management.

However, static IP address assignment has its limitations as well. It can be time-consuming and error-prone, especially in large networks with numerous devices. Any changes to the network topology or addition/removal of devices may require manual reconfiguration of IP addresses, which can be a tedious task.

Furthermore, static allocation can lead to inefficient utilization of available IP addresses. Each device is assigned a fixed address regardless of whether it is actively using the network or not. This can result in wastage of unused addresses and may pose challenges in scenarios where addressing space is limited.

In order to efficiently allocate IP addresses within a network, there are several important considerations that need to be taken into account. By carefully planning and managing the allocation process, network administrators can optimize their IP address usage and ensure smooth operation of their network.

One of the key factors to consider when assigning IP addresses is the size of the network. The number of devices that will be connected to the network determines the range of IP addresses that will be required. It is essential to accurately estimate the number of devices that will need an IP address in order to avoid running out of available addresses or wasting them unnecessarily.

Another consideration is the type of devices that will be connected to the network. Different devices have different requirements in terms of IP address assignment. For example, servers and other critical infrastructure typically require static IP addresses for stability and ease of access. On the other hand, client devices such as laptops and smartphones can often use dynamic IP addresses assigned by a DHCP server.

The physical layout of the network is also an important factor to consider. In larger networks with multiple subnets or VLANs, it may be necessary to segment IP address ranges accordingly. This allows for better organization and management of IP addresses, making it easier to troubleshoot issues and implement security measures.

Security is another crucial consideration when allocating IP addresses. Network administrators should implement measures such as firewalls and intrusion detection systems to protect against unauthorized access or malicious activities. Additionally, assigning unique IP addresses to each device enables better tracking and monitoring, facilitating quick identification and response in case of any security incidents.

Efficient utilization of IP address ranges can also be achieved through proper documentation and record-keeping. Maintaining an up-to-date inventory of all assigned IP addresses helps prevent conflicts or duplicate assignments. It also aids in identifying unused or underutilized portions of the address space, allowing for more efficient allocation in the future.

Furthermore, considering future growth and scalability is essential when allocating IP addresses. Network administrators should plan for potential expansion and allocate IP address ranges accordingly. This foresight ensures that there will be sufficient addresses available to accommodate new devices or additional network segments without disrupting the existing infrastructure.

In any network, the assignment of IP addresses is a crucial aspect that allows devices to communicate with each other effectively. When it comes to IP address assignment in the same network, there are specific considerations and methods to ensure efficient allocation. In this section, we will delve into how two routers in the same network obtain IP addresses and discuss subnetting and IP address range distribution.

To understand how two routers in the same network obtain IP addresses, it's essential to grasp the concept of subnetting. Subnetting involves dividing a larger network into smaller subnetworks or subnets. Each subnet has its own unique range of IP addresses that can be assigned to devices within that particular subnet. This division helps manage and organize large networks efficiently.

When it comes to assigning IP addresses within a subnet, there are various methods available. One common method is manual or static IP address assignment. In this approach, network administrators manually assign a specific IP address to each device within the network. Static IP addresses are typically used for devices that require consistent connectivity and need to be easily identifiable on the network.

Another widely used method for IP address assignment is Dynamic Host Configuration Protocol (DHCP). DHCP is a networking protocol that enables automatic allocation of IP addresses within a network. With DHCP, a server is responsible for assigning IP addresses dynamically as devices connect to the network. This dynamic allocation ensures efficient utilization of available IP addresses by temporarily assigning them to connected devices when needed.

When considering efficient allocation of IP addresses in the same network, several factors come into play. One important consideration is proper planning and design of subnets based on anticipated device count and future growth projections. By carefully analyzing these factors, administrators can allocate appropriate ranges of IP addresses for each subnet, minimizing wastage and ensuring scalability.

Additionally, implementing proper security measures is crucial when assigning IP addresses in the same network. Network administrators should consider implementing firewalls, access control lists (ACLs), and other security mechanisms to protect against unauthorized access and potential IP address conflicts.

Furthermore, monitoring and managing IP address usage is essential for efficient allocation. Regular audits can help identify any unused or underutilized IP addresses that can be reclaimed and allocated to devices as needed. This proactive approach ensures that IP addresses are utilized optimally within the network.

The proper assignment of IP addresses is crucial for maintaining network security and efficiency. Throughout this guide, we have covered the basics of IP addresses, explored different methods of IP address assignment, and discussed considerations for efficient allocation.

In conclusion, understanding IP address assignment in the same network is essential for network administrators and technical professionals. By following proper allocation methods such as DHCP or static IP assignment, organizations can ensure that each device on their network has a unique identifier. This not only enables effective communication and data transfer but also enhances network security by preventing unauthorized access.

Moreover, considering factors like subnetting, scalability, and future growth can help optimize IP address allocation within a network. Network administrators should carefully plan and allocate IP addresses to avoid conflicts or wastage of resources.

Overall, a well-managed IP address assignment process is vital for the smooth functioning of any network. It allows devices to connect seamlessly while ensuring security measures are in place. By adhering to best practices and staying updated with advancements in networking technology, organizations can effectively manage their IP address assignments.

In conclusion, this guide has provided a comprehensive overview of IP address assignment in the same network. We hope it has equipped you with the knowledge needed to make informed decisions regarding your network's IP address allocation. Remember that proper IP address assignment is not only important for connectivity but also plays a significant role in maintaining online security and optimizing network performance.

Enhance Online Security: The Ultimate Guide to Conceal Your IP Address

Alternative Methods to Conceal Your IP Address Without a VPN

Maintain Privacy: Learn How to Alter Your IP Address

The Significance of IP Address for Online Security and Privacy

Comprehensive Handbook on VPNs, IP Addresses, and Proxy Servers

Ip Addresses For Network Devices: Best Practices And Recommendations

Assigning ip addresses to network devices.

Assigning Internet Protocol (IP) addresses is an essential task when configuring devices on computer networks and internetworks. Careful planning and strategic assignment of IP addresses provides networks with critical benefits such as optimized traffic flow, simplified management, and room for future expansion.

Benefits of Proper IP Addressing

Implementing an intentional and well-organized IP addressing scheme for routers, switches, servers, printers, computer workstations, mobile devices, and other networked equipment delivers major advantages for network manageability and performance.

• Optimizes traffic flow patterns by logically grouping devices into subnetworks
• Simplifies administration tasks such as managing access control lists and security policies
• Reduces subnetting complexity by allowing flexible expansion of number of hosts
• Enables location-based identification and management of devices
• Facilitates network segmentation for security zones, departments, etc.

IP Addressing Schemes

Public vs private ip addresses.

Public IP addresses uniquely identify networked devices across the Internet, while private IP addresses identify devices within internal networks only behind Network Address Translation (NAT). Most home networks utilize private addressing with routers assigning public addresses only when accessing the Internet.

Table of Contents

Static vs Dynamic IP Addresses

Network hosts may utilize static IP addressing, in which IP address assignments do not change, or dynamic IP addressing such as Dynamic Host Configuration Protocol (DHCP), in which devices are automatically assigned IP addresses from a pool that can be updated.

Best Practices

Plan your ip addressing scheme.

Prior to assigning IP addresses, an IP scheme should be carefully planned and documented. Important planning factors include:

• Number and locations of subnets needed
• Number of required host IP addresses per subnet
• Which private address ranges to utilize
• Grouping of devices by usage or department

Leave Room for Growth

Carefully determine current and future IP addressing needs and assign address ranges that allow room for growth. Strategies include:

• Assigning address blocks in multiples of 4, 8, 16 etc. to simplify binary math for future subnetting
• Selecting private address ranges with ample room for expansion such as 172.16.0.0/12
• Implementing subnet sizes greater than the number of hosts currently needed

Use Subnetting to Organize your Network

Leverage subnetting and Classless Inter-Domain Routing (CIDR) notation to segment networks in a hierarchical fashion for better traffic management and easier administration.

Assign Static IPs to Servers and Printers

Assign static IP addresses to servers, printers, and other infrastructure devices for reliability and consistency. Use memorable numbering patterns related to device function or location.

Use Dynamic IPs for Client Devices

Use DHCP to assign user workstations, laptops, and mobile devices addresses dynamically from a predefined numbering pool. This eases administration if devices are added, moved, reassigned, or removed.

Enable DHCP

Dynamic Host Configuration Protocol (DHCP) enables the automatic distribution of IP settings like IP addresses, DNS servers, default gateways etc. This reduces manual administration.

Document your IP Addressing Scheme

Fully document and regularly update details of the IP plan including subnet masks, address ranges, static assignments, and DHCP pools. This aids management and troubleshooting.

Common Mistakes to Avoid

Not future-proofing your ip scheme.

Failure to properly anticipate growth frequently results in address shortages, subnetting complexities, and redesigns. Assign address blocks appropriately sized for foreseeable expansion.

Using Random, Unorganized IP Address Assignments

Lack of planning leads to chaotic, hard-to-manage IP schemes prone to errors and hampering troubleshooting. Organize logically from the beginning.

Forgetting to Document your Scheme

Undocumented IP assignments complicate management, maintenance, and integration with other systems. Documentation is critical.

Example IP Addressing Schemes

Class c network with 2 subnets.

A class C private network using subnetting to create two segments, accommodating up to 62 hosts per subnet.

Small Business Network with VLANs

A small business using VLANs and a class B private network to logically segment departments, servers, WiFi, and IP cameras across multiple switches totaling up to 65534 host addresses.

Tools and Utilities for IP Address Management

Specialized network management software and IP address management (IPAM) tools can automate and simplify administering more advanced, dynamic networks with many subnets. Example utilities include SolarWinds IP Address Manager, Infoblox BloxOne, and phpIPAM.

Summary and Conclusion

Strategically assigning IP addresses to networked devices provides major benefits for enterprises and small networks alike when properly planned and documented. Leveraging logical organization, segmentation, and other best practices allows room for expansion while delivering simpler, more resilient IP infrastructure. Avoiding common errors like failing to plan for growth or document your scheme leads to more maintainable networks. As networks scale in complexity, purpose-built IPAM solutions can further aid administration.

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Best practice for assigning private IP ranges?

Is it common practice to use certain private IP address ranges for certain purposes?

I'm starting to look into setting up virtualization systems and storage servers. Each system has two NICs, one for public network access, and one for internal management and storage access.

Is it common for businesses to use certain ranges for certain purposes? If so, what are these ranges and purposes? Or does everyone do it differently?

I just don't want to do it completely differently from what is standard practice in order to simplify things for new hires, etc.

• virtualization
• storage-area-network

• I would modify that because there's more likely to be more than 254 devices on a floor than 254 floors in a building see google.com/… . So, use the first 200 addresses of the 3rd octet for floor, then use the last 54 addresses and the remaining octet for devices. That gives 254 * 54 devices possible. Printers, workstations, laptops, Internet of things (IOT)(the most overused hype word today followed by 'folks', 'technology') [Toaters, light switches, lighting controllers, coffee pots. –  Dennis Commented Jul 19, 2015 at 2:22

4 Answers 4

Most systems I've seen attempt to map the IP ranges to a hierarchy of geography and/or system components.

One employer tended to use:

10.building.floor.device (with non-user resource VLANs using 10.x.100.x to 10.x.120.x )

10.major_system.tier_or_subsystem.component

• @caelyx: this sounds like a good approach that I could make use of. thanks! –  Tauren Commented Mar 1, 2010 at 9:31
• @Tauren - no worries; happy to help! Thanks for the upvote :) –  caelyx Commented Mar 1, 2010 at 10:38
• 2 I would modify that because there's more likely to be more than 254 devices on a floor than 254 floors in a building see google.com/…. So, use the first 200 addresses of the 3rd octet for floor, then use the last 54 addresses and the remaining octet for devices. That gives 254 * 54 devices possible. Printers, workstations, laptops, Internet of things (IOT)(the most overused hype word today followed by 'folks', 'technology') [Toaters, light switches, lighting controllers, coffee pots. – Dennis just now edit –  Dennis Commented Jul 19, 2015 at 2:23

One thing I would suggest is to use randomly selected private ranges from the 10.0.0.0/8 block for all of your private addresses. This avoids lots of problems, particularly when setting up VPNs between home/partner networks and your corporate network. Most home routers (and many corporate setups) use 192.168.0.0/24 or 10.0.0.0/24, so you'll spend hours sorting out various connecticity issues when you try to establish connectivity between two private networks.

If, however, you chose a random range like 10.145.0.0/16, and then subnet from there, it is far less likely that you will "collide" with a business partner or home network's private IP range.

• 1 for site addressing you could subnet 10.0.0.0/24 and encode the longitude and latitude in the the spare octet's. ;-) –  The Unix Janitor Commented Mar 22, 2010 at 13:03
• Unless your sites are less than one degree apart. We had two offices a few city blocks apart at one point, which are less than 0.02 degrees apart in terms of lat/lon ;-) –  rmalayter Commented Mar 22, 2010 at 21:42
• 2 If this is a concern (and it's a reasonable one), then use the third private IP range: 172.(16-31).0.0/16. Most people don't even know it's there. I've only seen it in use in one place ever. –  Dan Pritts Commented Sep 24, 2012 at 15:47
• 1 @DanPritts Rackspace uses 172.16.0.0/12 extensively for hosting and cloud servers. Probably because of its "obscurity". As with 10.0.0.0/8, though, it's better to choose random bits of that space where possible to avoid potential collisions. –  rmalayter Commented Sep 24, 2012 at 21:59
• 1 @RyanTM wow, I never read the RFC that closely. Glad to see that my own conclusion based on painful experience actually fits with the standard. –  rmalayter Commented Nov 11, 2015 at 20:49

RFC1918 details the 3 IP blocks that are reserved for private address space. The 2 common ones are:

• 10.0.0.0 - 10.255.255.255 (10/8 prefix)
• 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

Less common is:

• 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)

If you're setting up a separate network for storage, it would probably make sense to choose an IP range similar but slightly different to what you are using for regular networking. Consistency is good, but using different IP ranges allows you to be connected to both networks simultaneously, for example if you need to look something up while doing management with your laptop?

• So my laptop gets an IP number in the 192.168.0.x range from DHCP. I'm thinking that my storage network should be in the 10.x.x.x range to keep them really separate. Is this common practice, or do many places use something lik 192.168.1.x for their storage? –  Tauren Commented Feb 27, 2010 at 8:03
• 3 172.16-31/16 also =) Not much used though. –  Antoine Benkemoun Commented Feb 27, 2010 at 9:43
• 2 @Tauren: 192.168.1.x/24 is as equally separate from 192.168.0.x/24 as 10.0.0.x/24 is. It can't be "more" or "less" separate. They are on different subnets, full stop... :) –  rytis Commented Feb 27, 2010 at 11:06
• That's true for computers, but not for the people that work on them. Keeping staff members non-confused is a good thing, and naming standards go a long way towards that. –  pboin Commented Feb 27, 2010 at 13:26
• @pulegium: yes, I understand they are actually separate, but I meant in the "human sense", like @pboin mentions. –  Tauren Commented Mar 1, 2010 at 9:27

There is about as much consensus on IP addressing as on server names (see this site ad naseum) it just comes down to personal preference - typically of the first guy to set it all up!

No there is no proper way of doing it - simply pick one of the the 3 RFC1918 ranges (cheers @Nic Waller), split it into subnets (traditionally /24s but /23s are becoming more popular). Assign one of the subnets for public access and one for private - job done. Really the hard part is setting up the VLANs and ACLs.

Personally I prefer using the 10.x.x.x range as I can type it quicker than the other two, but really it makes no difference unless you need the larger size (192.168.x.x gives you 256 subnets of 254 IP addresses whereas 10.x.x.x gives you 65,536).

I would not suggest mixing the ranges for instance having 192.168.x.x for private and 10.x.x.x for public, technically it shouldn't matter but it would be very confusing.

• @Jon, thanks for your suggestions. this helps confirm most of what I thought was the case. –  Tauren Commented Mar 1, 2010 at 9:29
• How can the 10.x.x.x range be public? If they are assigned to public devices accessing the net through a VPN? (Seems the only way) –  Dennis Commented Jul 18, 2015 at 19:45

You must log in to answer this question.

Not the answer you're looking for browse other questions tagged networking virtualization routing storage-area-network ..

• Featured on Meta
• We've made changes to our Terms of Service & Privacy Policy - July 2024
• Announcing a change to the data-dump process

Hot Network Questions

• Does the notion of "moral progress" presuppose the existence of an objective moral standard?
• Why do doctors always seem to overcharge for services?
• Blocking access to `*.php` in `.well-known`
• Usage of Tabular method for Integration by Parts
• What is the “history“ of mindfulness
• When Beatrix stops placing dominoes on a 5x5 board, what is the largest possible number of squares that may still be uncovered?
• How to extract pipe remnant from ground sleeve?
• F-test for nested GLM
• Absolute invisibility in cosmos
• Could mage hand be used for surgery on another creature?
• Private sector professional being screened out of PhD program
• parallelStream with collect method()
• Where is there is only set of odds ratio in ordinal logistic regression?
• Power harness on interconnected smoke detector
• The 'correct' way to draw a diagram
• Is "Non-Trivial amount of work" a correct phrase?
• How to become Emperor of the Galaxy
• How to design a resampling filter?
• Newtonian vs General Relativistic light deflection angle
• Why do repeating 8's show up more often in these decimals of square roots?
• One Page IDP issued by Govt. Of India not acceptable in Japan
• What acceleration features did 2D PC video cards have? Comparing to video game consoles
• What's another word for utopian
• How are multiple sections of a large course assigned?

Best Practices for Efficient IP Address Management

As the digital landscape continues to expand exponentially, we’re seeing an unprecedented explosion in IP addresses. This surge is fuelled by the ever-increasing number of connected devices, applications, and the growing demand for mobility. Consequently, we find ourselves navigating an increasingly complex network environment. The management of these networks, in particular IP Address Management (IPAM), now faces a chief challenge and priority: simplification.

What is IP Address Management?

IP Address Management, often abbreviated as IPAM , is a method that allows network administrators to manage and track IP addresses within their network. When properly implemented, it can reduce the complexity and time spent on administrative tasks.

IP Address Allocation

IP Address Allocation refers to the assignment of IP addresses to devices within a network. The process should be well-planned, factoring in the current and future needs of the network. An effective IP plan ensures efficient utilization of address space, helping to optimize IP management.

IP Address Tracking

Keeping track of each allocated IP address is vital for maintaining network integrity. IP Address Tracking allows administrators to monitor the status of each IP address within their network, making it easier to identify any issues or conflicts. It contributes to the optimization of IP addresses allocated, preventing wastage of resources.

IP Address Management Solutions

To simplify this process, businesses are turning to robust IPAM solutions. These systems integrate with DNS and DHCP servers to manage, monitor, and record IP address configurations automatically. Adopting an IPAM solution is one of the IPAM best practices that aids in simplifying and streamlining, improving overall network management.

Best practices

Centralizing ip address management.

Centralizing your IP address management is a fundamental best practice. By consolidating all your IP address data in one location, you can easily keep tabs on your network’s health and promptly identify any potential conflicts or security risks.

Planning for Growth

Keeping an eye on the future is crucial. As your network expands, you’ll need to accommodate more devices and applications. Therefore, your IP address management should be scalable and flexible, ensuring it can handle future growth with ease.

Documenting IP Address Usage

Maintaining up-to-date documentation of your IP addresses is key to effective management. This aids in tracking which addresses are in use and which are available, facilitating efficient allocation and preventing conflicts.

Using DHCP for Dynamic IP Address Assignment

The Dynamic Host Configuration Protocol ( DHCP ) is a valuable tool for managing IP addresses. It automates the assignment of IP addresses, freeing up administrators to focus on other tasks and ensuring optimal use of address spaces.

Subnetting is the practice of dividing a network into smaller, more manageable parts. This technique enhances network performance and security, and it’s an essential component of effective IP address management.

Implement IP Address Security

Securing IP addresses is paramount to protect your network from attacks. This includes practices like setting up firewalls, restricting access to certain IP addresses, and regularly updating security patches.

Regularly Audit IP Address Usage

Regular audits of IP address usage help ensure the network is running optimally. They provide crucial insights into your IP address allocation, allowing you to identify patterns, track usage, and spot potential issues before they escalate.

IPAM Automation for Enhanced Efficiency

Ipam automation.

IPAM can save organizations time and money by automating the potentially tedious process of assigning and tracking IP addresses throughout their network. This means that organizations can spend their valuable resources on other important initiatives, allowing them to optimize the performance of their infrastructure in a timely manner. With the help of IPAM, managing large networks has become much simpler, making it more cost-effective in the long run.

Integrating IPAM with Other Management Services

Many businesses use various network management services such as Virtual Private Networks (VPN), Network Access Control (NAC), or Remote Authentication Dial-In User Service (RADIUS). Integrating your IPAM solution with these services can streamline network management, reducing the potential for errors and conflicts.

Wrapping up

Efficient IP Address Management is critical for maintaining a well-functioning network. By following these best practices and adopting an automated IPAM solution, businesses can optimize their IP addresses, streamline administrative tasks, and improve overall network management. With the ever-increasing demand for connectivity and mobility, now is the time to prioritize efficient IP address management within your organization. 

+1 (801) 819-7525 [email protected]

563 W 500 S Suite #300 Bountiful Utah 84010

• Link to LinkedIn
• Privacy Policy
• Tech Sheet Download
• Request a Demo

+1 (801) 819-7525

[email protected]

563 W 500 S Suite #300   Bountiful Utah 84010

Blog Category

• Career Tips
• Job Hunting
• Making Money
• All Featured
• All Hall of Fame
• Network Management
• Study Tools
• Troubleshooting
• All Uncategorized

CBT IT Certification Training

Unlimited IT Certification Courses via Streaming Video

Remember me

• Lost your password?

Enter your username or email:

• Back to login

Network Design – Designing Advanced IP Addressing

October 19, 2021 By Paul Browning Leave a Comment

This blog post covers the following network design topics:

• Summarizable and structured addressing designs
• IPv6 for Enterprise Campus design considerations

When designing IP addressing at a professional level, several issues must be taken into consideration. This blog post will cover generic IP addressing designs, including subnets and summarizable blocks design recommendations, address planning, and advanced addressing concepts, in addition to IPv6 design considerations, which will be covered in the last section of the post.

Importance of IP Addressing for Network Design

One of the major concerns in the network design phase is ensuring that the IP addressing scheme is properly designed. This aspect should be carefully planned and an implementation strategy should exist for the structural, hierarchical, and contiguous allocation of IP address blocks. A solid addressing scheme should be hierarchical, structural, and modular .

These features will add value to the continually improving concept of the Enterprise Campus design. This is also important in scaling any of the dynamic routing protocols. A solid IP addressing scheme helps routing protocols function in an optimal manner, using RIPv2, EIGRP, OSPF, or BGP. Facilitating summarization and the ability to summarize addresses provides several advantages for the network:

• Shorter Access Control Lists (ACLs)
• Reduces the overhead on routers (the performance difference is noticeable, especially on older routers)
• Faster convergence of routing protocols
• Addresses can be summarized to help isolate trouble domains
• Overall improvement of network stability

Address summarization is also important when there is a need to distribute addresses from one routing domain into another, as it impacts both the configuration effort and the overhead in the routing processing. In addition, having a solid IP addressing scheme not only makes ACLs easier to implement and more efficient for security, policy, and QoS purposes, but also it facilitates advanced routing policies and techniques (such as zone-based policy firewalls), where modular components and object groupings that are based on the defined IP addressing schemes can be created.

Solid IP address planning supports several features in an organization:

• Route summarization
• A more scalable network
• A more stable network
• Faster convergence

Subnet Network Design Recommendations

The importance of IP addressing is reflected in the new requirements that demand greater consideration of IP addressing, as the following examples illustrate:

• The transition to VoIP Telephony and the additional subnet ranges required to support voice services. Data and voice VLANs are usually segregated, and in some scenarios, twice as many subnets may be needed when implementing Telephony in the network .
• Layer 3 switching at the edge, replacing the Layer 2 switching with multi-layer switches. This involves more subnets needed at the Enterprise Edge, so t he number of smaller subnets will increase . There should be as little re-addressing as necessary, and making efficient use of the address space should be a priority. Sometimes, Layer 3 switching moved to the edge will involve a redesign of the IP addressing hierarchy.
• The company’s needs are changing and sometimes servers will be isolated by functions or roles (also called segmentation). For example, the accounting server, the development subnets, and the call-center subnets can be separated from an addressing standpoint. Identifying the subnets and ACLs based on corporate requirements can also add complexity to the environment .
• Many organizations use technologies like Network Admission Control (NAC), Cisco 802.1x (IBNS), or Microsoft NAP. These types of deployments will be dynamically assigning VLANs based on the user login or port-based authentication. In this situation, an ACL can actually manage connectivity to different servers and network resources based on the source subnet (which is based on the user role). Using NAC over a wired or wireless network will add more complexity to the IP addressing scheme.
• Many network topologies involve having separated VLANs (i.e., data, voice, and wireless). Using 802.1x may also involve a guest VLAN or a restricted VLAN , and authorization policies can be assigned based on VLAN membership from an Authentication, Authorization, and Accounting (AAA) server.
• Using role-based security techniques might require different sets of VPN clients, such as administrators, customers, vendors, guests, or extranets, so different groups can be implemented for different VPN client pools. This role-based access can be managed through a group password technique for each Cisco VPN client; every group can be assigned a VPN endpoint address from a different pool of addresses. If the pools are subnets of a summarizable block, then routing traffic back to the client can also be accomplished in a simplified fashion.
• Network designers should also consider that Network Address Translation (NAT) and Port Address Translation (PAT) can be applied on customer edge routers (often on the PIX firewall or on the ASA devices). NAT and PAT should not be used internally on the LAN or within the Enterprise Network to simplify the troubleshooting process. NAT can be used in a data center to support the Out-of-Band (OOB) management of the VLAN (i.e., on devices that cannot route or cannot find a default gateway for the OOB management of the VLAN).

You can read Ciscos network design guide here .

Summarization

After planning the network design for a IPv4 addressing scheme and determining the number and types of necessary addresses, a hierarchical design might be necessary. This design is useful when finding a scalable solution for a large organization and this involves address summarization. Summarization reduces the number of routes in the routing table and involves taking a series of network prefixes and representing them as a single summary address. It also involves reducing the CPU load and the memory utilization on network devices. In addition, this technique reduces processing overhead because routers advertise a single prefix instead of many smaller ones.

A summarizable address is one that contains blocks with sequential numbers in one of the octets . The sequential patterns must fit a binary bit pattern, with X numbers in a row, where X is a power of 2. The first number in this sequence must be a multiple of X. For example, 128 numbers in a row could be summarized with multiples starting at 0 or 128. If there are 64 numbers in a row (2 6 ), these will be represented in multiples of 64, such as 0, 64, 128, or 192, and 32 numbers in a row can be summarized with the multiples 0, 32, 64, and so on. This process can be easily accomplished using software subnet calculators.

Another planning aspect of summarizable blocks involves medium or large blocks of server farms or data centers. Servers can be grouped based on their functions and on their level of mission criticality, and they can all be in different subnets. In addition, with servers that are attached to different Access Layer switches, it is easier to assign subnets that will provide a perfect pattern for wildcarding in the ACLs. Simple wildcard rules and efficient ACLs are desired, as complex ACLs are very difficult to deal with, especially for new engineers who must take over an existing project.

When implementing the hierarchical addressing scheme for network design, it is important to have a good understanding of the math behind it and how route summarization works. Below is an example of combining a group of Class C addresses into an aggregate address. Summarization is a way to represent several networks in a single summarized route. In a real-world scenario, a subnet calculator can be used to automatically generate the most appropriate aggregate route from a group of addresses.

In this example, the Enterprise Campus backbone (Core Layer) submodule is connected to several other buildings. In a single building, there are several networks in use:

• A network for the server farm
• A network for the management area
• A few networks for the Access Layer submodule (that serve several departments)

The goal is to take all of these networks and aggregate them into one single address that can be stored at the edge distribution submodule or at the Core Layer of the network. The first thing to understand when implementing a hierarchical addressing structure is the use of continuous blocks of IP addresses . In this example, the addresses 192.100.168.0 through 192.100.175.0 are used:

In this scenario, network design summarization will be based on a location where all of the uppermost bits are identical. Looking at the first address above, the first 8 bits equal the decimal 192, the next 8 bits equal the decimal 100, and the last 8 bits are represented by 0. The only octet that changes is the third one; to be more specific, only the last 3 bits in that octet change when going through the address range.

The summarization process requires writing the third octet in binary format and then looking for the common bits on the left side. In the example above, all of the bits are identical up to the last three bits in the third octet. With 21 identical bits, all of the addresses will be summarized to 192.100.168.0/21.

After deciding on a hierarchical addressing design and understanding the math involved in this process, the next approach will be a modular and scalable design, which will involve deciding how to divide the organization (i.e., Enterprise Network modules, submodules, and remote locations) in terms of addressing. This includes deciding whether to apply a hierarchical address to each module/submodule or to the entire Enterprise Network.

Another aspect to consider is the way summarization may affect the routing protocols used. Summarization usually affects routing because it reduces the size of the routing tables, the processor, and memory utilization, and it offers a much faster convergence of the routed network. The following are the most important advantages of using route aggregation:

• Lower device processing overhead
• Improved network stability
• Ease of future growth

Figure 1 below offers another example of a large organization network design using a campus with multiple buildings:

Figure 1 – Network Design Addressing for a Large Organization with Multiple Buildings

The internal private addressing will use the popular 10.0.0.0/8 range. Within the organization’s domain, two separate building infrastructures (on the same campus or in remote buildings) will be aggregated using the 10.128.0.0/16 and 10.129.0.0/16 ranges.

Going deeper within each building, the addressing scheme can be broken down within different departments, using the 10.128.1.0, 10.128.2.0 or the 10.129.1.0, 10.128.2.0 networks with a 24-bit mask. Because of the scalable design, another tier could be included above the departmental addresses that would be within the 10.129.0.0/21 range, for example. Moving beyond that point leads to the Enterprise Edge module and its various submodules (e.g., e-commerce, Internet connectivity, etc.) that can have point-to-point connections to different ISPs. Variable Length Subnet Masking (VLSM) can be used to break down the addressing scheme further.

To summarize, from a network designer standpoint, it is very important to tie the addressing scheme to the modular Enterprise Network design . The advantages of using route summarization and aggregation are numerous but the most important ones are as follows:

• Isolates changes to the topology to a particular module
• Isolates routing updates to a particular module
• Fewer updates need to be sent up the hierarchy (preventing all of the updates from going through the entire network infrastructure)
• Lower overall recalculation of the entire network when links fail (e.g., a change in a routing table does not converge to the entire network); for example, route flapping in a particular department is constrained within the specific department and does not have a cascading effect on other modules (considering the example above)
• Narrow scope of route advertisement propagation
• Summarized module is easier to troubleshoot

Routing Protocols and Summarization for Network Design

Different routing protocols handle summarization in different manners. Routing Information Protocol (RIP) version 2 (RIPv2) has classful origins (it summarizes by default), although it can act in a classless manner because it sends subnet mask information in the routing updates.

Because of its classful origins, RIPv2 performs automatic summarization on classful boundaries, so any time RIPv2 is advertising a network across a different major network boundary, it summarizes to the classful mask without asking for permission. This can lead to big problems in the routing infrastructure of discontiguous networks. RIPv2’s automatic summarization behavior should be disabled in many situations to gain full control of the network routing operations.

In addition to the automatic summarization feature, RIPv2 allows for manual route summarization to be performed at the interface level . The recommendation is to disable automatic summarization and configure manual summarization where necessary. RIPv2 does not allow for summarization below the classful address. The next example involves the following prefixes:

210.22.10.0/24

210.22.9.0/24

210.22.8.0/24

RIPv2 will not allow the summarization of addresses above a /22 address because these are Class C addresses, and this would involve trying to summarize beneath this class. This is a limitation due to the classful origin of RIP.

EIGRP functions similar to RIPv2 regarding summarization, as EIGRP also has classful origins because it is an enhanced version of the Interior Gateway Routing Protocol (IGRP). EIGRP automatically summarizes on classful boundaries and, just like with RIPv2, this feature can be disabled and manual summarization can be configured on specific interfaces. The biggest issue with this behavior is that there might be discontiguous networks and this could cause problems with any of the automatic summarization mechanisms described.

Figure 2 – Discontiguous Network Issue

An example of a discontiguous network issue is illustrated in Figure 2 above. The 172.16.10.0/24 subnet is on the left side and the 172.16.12.0/24 subnet is on the right side. These networks are divided by a different major network in the middle (172.20.60.0/24), which causes a problem. Applying EIGRP in this scenario, automatic summarization will be enabled by default, with summarization toward the middle of the topology (172.16.0.0) from both sides, and this will cause great confusion to that device. As a result of this confusion, the device might send one packet to the left side and one packet to the right side, so there will be packets going in the wrong direction to get to a particular destination. To solve this issue, the automatic summarization feature should be disabled in discontiguous networks. Another possible fix to this problem is designing the addressing infrastructure better so that no discontiguous subnets are present.

OSPF does not have an automatic summarization feature but two different forms of summarization can be designed:

• Summarization between the internal areas
• Summarization from another separate domain

Two separate commands are used to handle these different summarization types. Summarizing from one area to another involves a Type 3 Link-State Advertisement (LSA). Summarizing from another domain involves two types of LSAs in the summarization process: a Type 4 LSA, which advertises the existence of the summarizing device (e.g. the OSPF Autonomous System Border Router – ASBR), and the actual summary of information, carried in a Type 5 LSA.

Border Gateway Protocol (BGP) uses a single type of summarization called aggregation , and this is accomplished during the routing process. BGP is used to summarize automatically, just like RIPv2 and EIGRP, but this behavior has been automatically disabled by the 12.2(8)T IOS code.

Variable Length Subnet Masking and Structured Addressing

A structured addressing plan involves the concept of Variable Length Subnet Masking (VLSM), a technology that all of the modern routing protocols can easily handle. VLSM provides efficiency, as it disseminates an addressing plan that does not waste address space (i.e., it assigns only the number of addresses needed for a certain subnetwork). VLSM also accommodates efficient summarization. The most important benefits of VLSM and summarization include the following:

• Less CPU utilization on network devices
• Less memory utilization on network devices
• Smaller convergence domains

Figure 3 – VLSM Example (Part 1)

VLSM functions by taking unused subnets from the address space used and further subnets them. Figure 3 above starts with the major network of 172.16.0.0/16 (not shown in the example), which is initially subnetted using a 24-bit mask, resulting in two large subnets on the two router interfaces (Fa0/0 and Fa0/1), 172.16.1.0/24 and 172.16.2.0/24, respectively. Two key formulas can be used when calculating the number of subnets and hosts using VLSM. An example of the subnet and host split in the address is shown below in Figure 4:

Figure 4 – VLSM Subnet and Host Split

The formula for calculating the number of subnets is 2 s , where “s” is the number of borrowed subnet bits. In Figure 3.3 above, the network expanded from a /16 network to a /24 network by borrowing 8 bits. This means 2 8 = 256 subnets can be created with this scheme.

The formula for calculating the number of hosts that can exist in a particular subnet is 2 h -2, where “h” is the number of host bits. Two hosts are subtracted from the 2 h formula because the all-zeros host portion of the address represents the major network itself and the all-ones host portion of the address represents the broadcast address for the specific segment, as illustrated below:

• Major networks (all zeros in the host portion): 172.16.1.0 and 172.16.2.0
• Broadcast networks (all ones in the host portion): 172.16.1.255 and 172.16.2.255

After summarizing the 172.16.0.0/16 address space into 172.16.1.0/24 and 172.16.2.0/24, further subnetting might be needed to accommodate smaller networks, which can be achieved by taking one of the next available subnets (after the subnetting process), for example, 172.16.3.0/24. This will create additional subnets such as those below:

172.16.3.32/27

172.16.3.64/27

The /27 subnets are suitable for smaller networks and can accommodate the number of machines in those areas. The number of hosts that can be accommodated is 2 5 -2=30.

Figure 5 – VLSM Example (Part 2)

A subnet might be needed for the point-to-point link that will connect two network areas, and this can be accomplished by further subnetting one of the available subnets in the /27 scheme, for example 172.16.3.96/27. This can be subnetted with a /30 to obtain 172.16.3.100/30, which offers just two host addresses: 172.16.3.101 and 172.16.3.102. This scheme perfectly suits the needs for the point-to-point connections (one address for each end of the link). By performing VLSM calculations, subnets that can accommodate just the right number of hosts in a particular area can be obtained.

Private versus Public Addressing

As a network design expert, after determining the number of necessary IP addresses, the next big decision is to find out whether private, public, or a combination of private and public addresses will be used. Private internetwork addresses are defined in RFC 1918 and are used internally within the network. From a real-world standpoint, because of the limitation of the number of public IP addresses, NAT techniques are usually used to translate the private internal numbers to external public addresses. Internally, one of the following three ranges of addresses can be used:

• 0.0.0/8 (10.0.0.0 to 10.255.255.255), usually used in large organizations
• 16.0.0/12 (172.16.0.0 to 172.31.255.255), usually used in medium organizations
• 168.0.0/16 (192.168.0.0 to 192.168.255.255), usually used in small organizations

Any address that falls within the three private address ranges cannot be routed on the Internet. Service Provider Edge devices usually have policies and ACLs configured to ensure that any packet containing a private address that arrives at an inbound interface will be dropped.

All of the other addresses are public addresses that are allocated to ISPs or other point of presence nodes on the Internet. ISPs can then assign Class A, B, or C addresses to customers to use on devices that are exposed to the Internet, such as:

• Web servers
• DNS servers
• FTP servers
• Other servers that run public-accessible services

When deciding to use private, public, or a combination of private and public addresses for your network design, one of the following four types of connections will be used:

• No Internet connectivity
• Only one public address (or a few) for users to access the Web
• Web access for users and public-accessible servers
• Every end-system has a public IP address

No Internet connectivity would imply that all of the connections between the locations are private links and the organization would not be connected to the Internet in any of its nodes. In this case, there is no need for any public IP addresses because the entire address scheme can be from the private address ranges.

Another situation would be the one in which there is Internet connectivity from all of the organization’s locations but there are no servers to run public-accessible services (e.g., Web, FTP, or others). In this case, a public IP address is needed that will allow users to access the Web. NAT can be used to translate traffic from the internal network to the outside network, so the internal networks contain only private IP addresses and the external link can use just one public address.

The third scenario is one of the most common, especially when considering the growth of enterprise networking. This involves having user Internet connectivity (just like in the previous scenario) but also having public-accessible servers. Public IP addresses must be used to connect to the Internet and access specific servers (e.g., Web, FTP, DNS, and others). The internal network should use private IP addresses and NAT to translate them into public addresses.

The most highly unlikely scenario would be the one in which every end-system is publicly accessible from the global Internet . This is a dangerous situation because the entire network is exposed to Internet access and this implies high security risks. To mitigate these risks, strong firewall protection policies must be implemented in every location. In addition to the security issues, this scenario is also not very effective because many IP addresses are wasted and this is very expensive. All of these factors make this scenario one not to be used in modern networks.

The two most common solutions from the scenarios presented above are as follows:

• One or a few public addresses for users to access the Web
• A few public addresses that provide Web access for users and public-accessible servers

Both scenarios imply using private internal addresses and NAT to reach outside networks.

For a deeper analysis of these aspects, it is useful to focus on how they map to the Cisco Enterprise Architecture model and where private and public addresses should be used, which is illustrated in Figure 6 below:

Figure 6 – Cisco Enterprise Architecture Model Addressing Scheme

First, in the figure above, assume that there is some kind of Internet presence in the organization that offers services either to internal users in the Access Layer submodule or to different public-accessible servers (e.g., Web, FTP, or others) in the Enterprise Edge module. Regardless of what modules receive Internet access, NAT is run in the edge distribution submodule to translate between the internal addressing structure used in the Enterprise Campus and the external public IP addressing structure. NAT mechanisms can also be used in the Enterprise Edge module.

Using the 10.0.0.0/8 range internally, both in the Enterprise Campus module and in the network management submodule, Enterprise Campus devices that use private IP addresses include all of its component submodules:

• Access Layer
• Distribution Layer
• Server farm

The edge distribution submodule will use a combination of private and public IP addresses. The Enterprise Edge module will use a combination of private and public addresses, depending on each submodule. The remote access submodule can use a combination of private and public addresses but it will need to support some kind of NAT techniques. The WAN submodule can use either private addresses (when connecting to other remote sites) or public addresses (when connected to outside locations for a backup solution).

Address Planning

An important issue in the IP addressing design is how the addresses will be assigned. One way would be to use static assigning and the other way would be to use dynamic protocols such as the Dynamic Host Configuration Protocol (DHCP). Deciding on the address allocation method requires answering the following questions:

• How many end-systems are there?

For a small number of hosts (less than 50), consider using statically/manually assigned addresses; however, if there are several hundred systems, use DHCP to speed up the address allocation process (i.e., avoid manual address allocation).

• What does the security policy demand?

Some organizations demand the use of static IP addressing for every host or for every node to create a more secure environment. For example, an outsider cannot plug in a station to the network, automatically get an IP address, and have access to internal resources. The organization’s security policy might demand static addressing, regardless of the network size.

• What is the likelihood of renumbering?

This includes the possibility of acquisitions and mergers in the near future. If the likelihood of renumbering is high, DHCP should be used.

• Are there any high availability demands?

If the organization has high availability demands, DHCP should be used in a redundant server architecture.

In addition, static addressing should always be used on certain modules in certain devices:

• Corporate servers
• Network management workstations
• Standalone servers in the Access Layer submodule
• Printers and other peripheral devices in the Access Layer submodule
• Public-accessible servers in the Enterprise Edge module
• Remote Access Layer submodule devices
• WAN submodule devices

Role-Based Addressing

From a Cisco standpoint, the best way to implement role-based addressing is to have it mapped to the corporate structure or to the roles of the servers or end-user stations. Using an example based on the 10.0.0.0/8 network, consider the first octet to be the major network number, the second octet to be the number assigned to the closet (i.e., the server room or wiring closets throughout the organization), the third octet to be the VLAN numbers, and the last octet to be the number of hosts. An address of 10.X.Y.Z would imply the following octet definitions:

• X = closet numbers
• Y = VLAN numbers
• Z = host numbers

This is an easy mechanism that can be used with Layer 3 closets. Role-based addressing avoids binary arithmetic , so if there are more than 256 closets, for example (more than can be identified in the second octet), some bits can be borrowed from the beginning of the third octet because there will not be 256 VLANs for every switch. Thereafter, advanced binary arithmetic or bit splitting can be used to adapt the addressing structure to specific needs. Bit splitting can be used with routing protocols, as well as route summarization, to help number the necessary summarizable blocks.  In this case, addresses will be split into a network part, an area part, a subnet part, and a host part.

Network designers might not always have the luxury of using the summarizable blocks around simple octet boundaries and sometimes this is not even necessary, especially when some bit splitting techniques would better accommodate the organization and the role-based addressing scheme. This usually involves some binary math, such as the example below:

172.16.aaaassss.sshhhhhh

The first octet is 172 and the second octet is 16. The “a” bits in the third octet identify the area and the “s” bits identify the network subnet or VLAN. Six bits are reserved for the hosts in the forth octet. This offers 62 hosts per VLAN or subnet, or 2 16 -2 (two host addresses will be reserved for the network address – all zeros in the last bits and the broadcast address and all ones in the last bits).

This logical scheme will result in the following address ranges, based on the network areas:

• Area 0: 172.16.0.0 to 172.16.15.255
• Area 1: 172.16.16.0 to 172.16.31.255
• Area 2: 172.16.32.0 to 172.16.47.255

Subnet calculations should be made to ensure that the right type of bit splitting is used to represent the subnet and VLANs. Remember that a good summarization technique is to take the last subnet in every area and divide it so that the /30 subnet can be used for any WAN or point-to-point links. This will maximize the address space so for each WAN link there will be only two addresses with a /30 or .252 subnet mask.

Most organizations have their addressing schemes mapped out onto spreadsheets or included in different reports and stored as part of their documentation for the network topology. This should be done very systematically and hierarchically, regardless of the addressing scheme used. Always take into consideration the possible growth of the company through mergers or acquisitions.

Network Address Translation Applications

Although the goal with IPv6 is to avoid the need for NAT, NAT for IPv4 will still be used for a while. NAT is one of the mechanisms used in the transition from IPv4 to IPv6, so it will not disappear any time soon. In addition, it is a very functional tool for working with IPv4 addressing. NAT and PAT (or NAT Overload) are usually carried out on ASA devices, which have powerful tools to accomplish these tasks in many forms:

• Dynamic NAT
• Identity NAT

A recommended best practice is to try to avoid using NAT on internal networks, except for situations in which NAT is required as a stop-gap measure during mergers or migrations. NAT should not be performed between the Access Layer and the Distribution Layer or between the Distribution Layer and the Core Layer. Following this recommendation will prevent address translation between OSPF areas, for example.

Organizations with a merger in progress usually use the same internal network addressing schemes and these can be managed with NAT overlapping techniques (also referred to as bidirectional NAT), which translates between the two organizations when they have an overlapping internal IP addressing space that uses RFC 1918 addressing.

If there are internal servers or servers in the DMZ that are reached using translated addresses, it is a good practice to isolate these servers into their own address space and VLAN, possibly using private VLANs. NAT is often used to support content load balancing servers, which usually must be isolated by implementing address translation.

NAT can also be used in the data center submodule to support a management VLAN that is Out-of-Band from production traffic. It should also be implemented on devices that cannot route or cannot define a gateway for the management VLAN. This results in smaller management VLANs, not a single large management VLAN that covers the entire data center. In addition, large companies or Internet entities can exchange their summary routes, and then they can translate with NAT blocks into the network. This will offer faster convergence but the downside is an increased troubleshooting process because of the use of NAT or PAT.

PAT is harder to troubleshoot because one or a few IP addresses are used to represent hundreds or even thousands of internal hosts, all using TCP and UDP ports to create logical sockets. This increases the complexity of the troubleshooting process because it is difficult to know what IP address is assigned to a particular host. Each host uses a shared IP address and a port number. If the organization is connected to several different partners or vendors, each partner can be represented by a different NAT block, which can be translated in the organization.

Network Design for IPv6 Addressing

CCDP certification requires a solid understanding of the IP version 6 specifications, addressing, and some of the design issues. The IPv6 protocol is based on RFC 2460. From a network designer standpoint, the most important features offered by IPv6 include the following:

• A 128-bit address space
• Supports hierarchical addressing and auto-configuration
• Every host can have a globally unique IPv6 address; no need for NAT
• Hosts can have multiple addresses
• Efficient fixed header size for IPv6 packets
• Enhanced security and privacy headers
• Improved multicasting and QoS
• Dedicated IPv6 routing protocols: RIPng, OSPFv3, Integrated IS-ISv6, BGP4+
• Every major vendor supports IPv6

IPv6 is a mechanism that was created to overcome the limitations of the current IPv4 standard . One of the major shortcomings of IPv4 is that it uses a 32-bit address space. Because of the classful system and the growth of the Internet, the 32-bit address space has proven to be insufficient. The key factors that led to the evolution of IPv6 were large institutions, Enterprise Networks, and ISPs that demanded a larger pool of IP addresses for different applications and services.

Address Representation

IPv4 uses a 32-bit address space, so it offers around 4.2 billion possible addresses, including the multicast, experimental, and private ones. The IPv6 address space is 128 bits, so it offers around 3.4×10 38 possible addressable nodes. The address space is so large that there are about 5×10 28 addresses per person in the world. IPv6 also gives every user multiple global addresses that can be used for a wide variety of devices (e.g., PDAs, cell phones, and IP-enabled devices). IPv6 addresses will last a very long time. An IPv6 packet contains the following fields, as depicted in Figure 7 below:

Figure 7 – IPv6 Packet Fields  

Knowing what is in the IPv4 header is important from a network designer standpoint because many of the fields in the header are used for features such as QoS or protocol type. The IPv6 header offers additional functionality, even though some fields from the IPv4 header have been eliminated, such as the Fragment Offset field and the Flags field.

The Version field, as in the IPv4 header, offers information about the IP protocol version. The Traffic Class field is used to tag the packet with the class of traffic it uses in its DiffServ mechanisms. IPv6 also adds a Flow Label field, which can be used for QoS mechanisms, by tagging a flow. This can be used for multilayer switching techniques and will offer faster packet switching on the network devices. The Payload Length field is the same as the Total Length field in IPv4.

The Next Header is an important IPv6 field. The value of this field determines the type of information that follows the basic IPv6 header. It can be a Transport Layer packet like TCP or UDP or it can designate an extension header. The Next Header field is the equivalent of the Protocol field in IPv4. The next field is Hop Limit, which designates the maximum number of hops an IP packet can traverse. Each hop/router decrements this field by one, so this is similar to the TTL field in IPv4. There is no Checksum field in the IPv6 header , so the router can decrement the Hop Limit field without recalculating the checksum. Finally, there is the 128-bit source address and the 128-bit destination address.

In addition to these fields there are a number of extension headers. The extension headers and the data portion of the packet will follow the eight fields covered thus far. The total length of an extension header’s chain can be variable because the number of extension headers is not fixed. There are different types of extension headers, such as the following:

• Routing header
• Fragmentation header
• Authentication header
• IPsec ESP header
• Hop-by-Hop Options header

The IPv4 address is comprised of a string of 32 bits represented in four octets using a dotted decimal format. IPv6, on the other hand, is comprised of 128 bits represented in eight groups of 16 bits using a hexadecimal format (i.e., 16 bits separated by colons), for example:

2001:43aa:0000:0000:11b4:0031:0000:c110.

Considering the complex format of IPv6 addresses, some rules were developed to shorten them:

• One or more successive 16-bit groups that consist of all zeros can be omitted and represented by two colons (::).
• If a 16-bit group begins with one or more zeros, the leading zeros can be omitted.

Considering the IPv6 example above, here are its shortened representations:

2001:43aa::11b4:0031:0000:c110

2001:43aa::11b4:0031:0:c110

2001:43aa::11b4:31:0:c110

In a mixed IPv4 and IPv6 environment, the IPv4 address can be embedded in the IPv6 address, specifically in the last 32 bits.

The prefix portion in IPv6 is the number of contiguous bits that represent the network host. For example, the address 2001:0000:0000:0AABC:0000:0000:0000:0000/60 can be represented as 2001:0:0:ABC::/60.

Several types of IPv6 addresses are required for various applications. When compared to IPv4 address types (i.e., unicast, multicast, and broadcast), IPv6 presents some differences: special multicast addresses are used instead of broadcast addressing, and a new address type was defined called anycast.

Anycast addresses are generally assigned to servers located in different geographical locations. By connecting to the anycast address, users will reach the closest server. Anycast addresses are also called one-to-nearest addresses. The IPv6 multicast address is a one-to-many address that identifies a set of hosts that will receive the packet. This is similar to an IPv4 Class D multicast address . IPv6 multicast addresses also supersede the broadcast function of IPv4 broadcast. IPv6 broadcast functionality is an all-nodes multicast behavior. The following are well-known multicast addresses that should be remembered:

• FF01::1 = all-nodes multicast address (broadcast)
• FF02::2 = all-routers multicast address (used for link-local address mechanisms)

Another important multicast address is the solicited node multicast address, which is created automatically and placed on the interface. This is used by the IPv6 Neighbor Discovery process to improve upon IPv4 ARP. A special IPv6 address is 0:0:0:0:0:0:0:1, which is the IPv6 loopback address, equivalent to the 127.0.0.1 IPv4 loopback address. This can also be represented as ::1/128.

The link-local addresses are significant only to individual nodes on a single link. Routers forward packets with a link-local source or destination address beyond the local link. Link-local addresses can be configured automatically or manually. Global unicast addresses are globally unique and routable and are defined in RFC 2374 and RFC 3587.

Figure 8 – IPv6 Global Unicast Address Format

Based on the IPv6 global unicast address format shown in Figure 8 above, the first 23 bits represent the registry, the first 32 bits represent the ISP prefix, the first 48 bits are the site prefix, and /64 represents the subnet prefix. The remaining bits are allocated to the interface ID.

The global unicast address and the anycast address share the same format. The unicast address space actually allocates the anycast address. To devices that are not configured for anycast, these addresses will appear as unicast addresses.

IPv6 global unicast addressing allows aggregation upward to the ISP. A single interface may be assigned multiple addresses of any type (i.e., unicast, anycast, and multicast). However, every IPv6-enabled interface must have a loopback address and a link-local address.

The IPv6 global unicast address is structured as presented above in Figure 3.8 to facilitate aggregation and reduce its number in the global routing tables, just like with IPv4. Global unicast addresses are defined by a global routing prefix, a subnet ID, and an interface ID. Typically, a global unicast address is made up of a 48-bit global routing prefix and a 16-bit subnet identifier.

IPv6 Mechanisms

As with IPv4, there are different mechanisms available for IPv6 and the most important of these includes the following:

• IPv6 Neighbor Discovery (ND)
• Name resolution
• Path Maximum Transmission Unit (MTU) Discovery
• IPv6 security
• IPv6 routing protocols

The Internet Control Message Protocol (ICMP) was modified to support IPv6 and is one of the most important mechanisms that support IPv6 functionality. ICMPv6 uses a Next Header number of 58. ICMP provides informational messages (e.g., Echo Request and Echo Reply) and error messages (e.g., Destination Unreachable, Packet Too Big, and Time Exceeded). IPv6 also uses ICMPv6 to determine important parameters, such as neighbor availability, Path MTU Discovery, destination addresses, or port reachability.

IPv6 uses a Neighbor Discovery protocol (RFC 2461), unlike IPv4, which uses the Address Resolution Protocol (ARP). IPv6 hosts use ND to implement “plug and play” functionality and to discover all other nodes on the same link. ND is also used in checking for duplicate addresses and finding the routers on a specific link. ND uses the ICMPv6 message structure in its operations and its type codes are 133 through 137:

• Router Solicitation
• Router Advertisement
• Neighbor Solicitation
• Neighbor Advertisement

Neighbor Discovery goes beyond the capabilities of ARP, as it performs many functions:

• Address Auto-Configuration (a host can find its full address without using DHCP)
• Duplicate Address Detection (DAD)
• Prefix Discovery (learns prefixes on local links)
• Link MTU Discovery
• Hop Count Discovery
• Next-Hop Determination
• Address Resolution
• Router Discovery (allows routers to find other local routers)
• Neighbor Reachability Detection
• Redirection
• Proxy Behavior
• Default Router Selection

Many of the features mentioned above have IPv4 equivalencies but some of them are unique to IPv6 and provide additional functionalities.

One of the important features made possible by the ND process is DAD, as defined in RFC 4862. This is accomplished through Neighbor Solicitation messages that are exchanged before the interface is allowed to use a global unicast address on the link, and this can determine whether the particular address is unique. The Target Address field in these specific packets is set to the IPv6 address for which duplication is being detected and the source address is set to unspecified (::).

The IPv6 stateless Auto-Configuration feature avoids using DHCP to maintain a mapping for the address assignment. This is a very low-overhead manner in which to disseminate addresses and it accommodates low-overhead re-addressing. In this process, the router sends a Router Advertisement message to advertise the prefix and its ability to act as a default gateway. The host receives this information and uses the EUI-64 format to generate the host portion of the address. After the host generates the address, it starts the DAD process to ensure that the address is unique on the network.

IPv4 performs Name Resolution by using A records in the DNS. RFC 3596 offers a new DNS record type to support the transition to IPv6 Name Resolution, which is AAAA (Quad A). The Quad A record will return an IPv6 address based on a given domain name.

IPv6 does not allow packet fragmentation through the network (except for the source of the packet), so the MTU of every link in an IPv6 implementation must be 1280 bytes or greater. The ICMPv6 Packet Too Big error message determines the path MTU because nodes along the path will send this message to the sending hosts if the packet is larger than the outgoing interface MTU.

DHCPv6 is an updated version of DHCP that offers dynamic address assignment for version 6 hosts. DHCPv6 is described in RD 3315 and provides the same functionality as DHCP but it offers more control, as it supports renumbering without numbers.

IPv6 also has some security mechanisms. Unlike IPv4, IPv6 natively supports IPsec (an open security framework) with two mechanisms: the Authentication Header (AH) and the Encapsulating Security Payload (ESP).

The support for IPsec in IPv6 is mandatory, unlike with IPv4. By making it mandatory in all the IPv6 nodes, secure communication can be created with any node in the network. An example of mandatory and leveraged IPsec in IPv6 is OSPF, which carries out its authentication using only IPsec. Another example of the IPsec IPv6 mechanism is the IPsec Site-to-Site Virtual Tunnel Interface, which allows easy creation of virtual tunnels between two IPv6 routers to very quickly form a site-to-site secured Virtual Private Network (VPN).

The following new routing protocols were developed for IPv6:

• RIPng (RIP new generation)
• Integrated Intermediate System-to-Intermediate System Protocol (IS-IS)
• EIGRP for IPv6
• BGP4 multiprotocol extensions for IPv6

Transitioning from IPv4 to IPv6

Because IPv6 almost always comes as an upgrade to the existing IPv4 infrastructure, IPv6 network design and implementation considerations must include different transition mechanisms between these two protocol suites. The IPv4 to IPv6 transition can be very challenging, and during the transition period it is very likely that both protocols will coexist on the network .

The designers of the IPv6 protocol suite have suggested that IPv4 will not go away anytime soon, and it will strongly coexist with IPv6 in combined addressing schemes. The key to all IPv4 to IPv6 transition mechanisms is dual-stack functionality, which allows a device to operate both in IPv4 mode and in IPv6 mode.

One of the most important IPv4 to IPv6 transition mechanisms involves tunneling between dual-stack devices and this can be implemented in different flavors:

• Generic Routing Encapsulation (GRE) – default tunnel mode
• IPv6IP (less overhead, no CLNS transport)
• 6to4 (embeds IPv4 address into IPv6 prefix to provide automatic tunnel endpoint determination); automatically generates tunnels based on the utilized addressing scheme
• Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) – automatic host-to-router and host-to-host tunneling

Figure 9 – IPv6 over IPv4 Tunneling

Analyzing Figure 9 above, the IPv4 island contains two dual-stack routers that run both the IPv4 and the IPv6 protocol stacks. These two routers will be able to support the transition mechanisms by tunneling IPv6 inside IPv4, and the two routers each connect to an IPv6 island. To carry IPv6 traffic between the two edge islands, a tunnel is created between the two routers that encapsulate IPv6 packets inside IPv4 packets. These packets are sent through the IPv4 cloud as regular IPv4 packets and they get de-encapsulated when they reach the other end. An IPv6 packet generated in the left-side network reaches a destination in the right-side network, so it is very easy to tunnel IPv6 inside IPv4 because of the dual-stack routers at the edge of the IPv4 infrastructure. Static tunneling methods are generally used when dealing with point-to-point links, while dynamic tunneling methods work best when using point-to-multipoint connections.

Network Address Translation Protocol Translation (NAT-PT) is another technology that can be utilized to carry out the transition to an IPv6 network. NAT-PT is often confused with NAT but it is a completely different technology. Simple NAT can also be used in IPv6 but this is very rare because IPv6 offers a very large address space and private addresses are not necessary. NAT-PT is another translation mechanism that will dynamically convert IPv4 addresses to IPv6 addresses, and vice-versa.

Another static tunneling technology is IPv6IP, which encapsulates IPv4 packets directly into IPv6. This is also called manual tunneling. Another type of static tunnel that can be created is a GRE tunnel that encapsulates the IPv6 packets within a GRE packet. GRE tunneling might be necessary when using special applications and services, like the IS-IS routing protocol for IPv6.

The dynamic tunnel types include the 6to4 tunnel, which is appropriate when a group of destinations needs to be connected dynamically utilizing IPv6. ISATAP is a unique type of host-to-router dynamic tunnel, unlike the previously mentioned tunneling techniques, which are router-to-router. ISATAP allows hosts to dynamically get to their IPv6 default gateway.

IPv6 Compared to IPv4

A network designer should have a very clear picture of the advantages IPv6 has over IPv4. The enhancements of IPv6 can be summarized as follows:

• IPv6 uses hexadecimal notation instead of dotted-decimal notation (IPv4).
• IPv6 has an expanded address space, from 32 bits to 128 bits .
• IPv6 addresses are globally unique due to the extended address space, eliminating the need for NAT.
• IPv6 has a fixed header length (40 bytes), allowing vendors to improve switching efficiency.
• IPv6 supports enhanced options (that offer new features) by placing extension headers between the IPv6 header and the Transport Layer header.
• IPv6 offers Address Auto-Configuration, providing for the dynamic assignment of IP addresses even without a DHCP server.
• IPv6 offers support for labeling traffic flows.
• IPv6 has security capabilities built-in, including authentication and privacy via IPsec
• IPv6 offers Path MTU Discovery before sending packets to a destination, eliminating the need for fragmentation.
• IPv6 supports site multi-homing.
• IPv6 uses the ND protocol instead of ARP.
• IPv6 uses AAAA DNS records instead of A records (IPv4).
• IPv6 uses site-local addressing instead of RFC 1918 (IPv4).
• IPv4 and IPv6 use different routing protocols.
• IPv6 provides for anycast addressing.

You can learn more about network design for security and wireless in our Cisco CCNP Encor course here .

Good IP addressing for network design uses summarizable blocks of addresses that enable route summarization and provide a number of benefits:

• Reduced router workload and routing traffic
• Increased network stability
• Significantly simplified troubleshooting

Creating and using summary routes depends on the use of summarizable blocks of addresses . Sequential numbers in an octet may denote a block of IP addresses as summarizable. For sequential numbers to be summarizable, the block must be X numbers in a row, where X is a power of 2, and the first number in the sequence must be a multiple of X. The created sequence will then end one before the next multiple of X in all cases.

Efficiently assigning IP addresses to the network is a critical network design decision, impacting the scalability of the network and the routing protocols that can be used. IPv4 addressing has the following characteristics:

• IPv4 addresses are 32 bits in length.
• IPv4 addresses are divided into various classes (e.g., Class A networks accommodate more than 16 million unique IP addresses, Class B networks support more than 65 thousand IP addresses, and Class C networks permit 254 usable IP addresses). Originally, organizations applied for an entire network in one of these classes. Today, however, subnetting allows an ISP to give a customer just a portion of a network’s address space, in an attempt to conserve the depleting pool of IP addresses. Conversely, ISPs can use supernetting (also known as Classless Inter-Domain Routing – CIDR) to aggregate the multiple network address spaces that they have. Aggregating multiple network address spaces into one address reduces the amount of route entries a router must maintain.
• Devices such as PCs can be assigned a static IP address, by hard coding the IP address in the device’s configuration. Alternatively, devices can dynamically obtain an address from a DHCP server , for example.
• Because names are easier to remember than IP addresses are, most publicly accessible Web resources are reachable by their name. However, routers must determine the IP address with which the name is associated to route traffic to that destination. Therefore, a DNS server can perform the translation between domain names and their corresponding IP addresses.
• Some IP addresses are routable through the public Internet, whereas other IP addresses are considered private and are intended for use within an organization. Because these private IP addresses might need to communicate outside the LAN, NAT can translate a private IP address into a public IP address. In fact, multiple private IP addresses can be represented by a single public IP address using NAT. This type of NAT is called Port Address Translation (PAT) because the various communication flows are identified by the port numbers they use to communicate with outside resources.

When beginning to design IP addressing for a network, the following aspects must be determined:

• The number of network locations that need IP addressing
• The number of devices requiring an IP address at each location
• Customer-specific IP addressing requirements (e.g., static IP addressing versus dynamic IP addressing)
• The number of IP addresses that need to be contained in each subnet (e.g., a 48-port switch in a wiring closet might belong to a subnet that supports 64 IP addresses)

A major challenge with IPv4 is the limited number of available addresses . A newer version of IP, specifically IPv6, addresses this concern. An IPv6 address is 128 bits long, compared to the 32-bit length of an IPv4 address.

To make such a large address more readable, an IPv6 address uses hexadecimal numbers and the 128-bit address is divided into eight fields. Each field is separated by a colon, as opposed to the four fields in an IPv4 address, which are each separated by a period. To further reduce the complexity of the IPv6 address, leading 0s in a field are optional and if one or more consecutive fields contain all 0s, those fields can be represented by a double colon (::). A double colon can be used only once in an address; otherwise, it would be impossible to know how many 0s are present between each pair of colons.

Consider some of the benefits offered by IPv6:

• IPv6 dramatically increases the number of available addresses.
• Hosts can have multiple IPv6 addresses, allowing those hosts to multi-home to multiple ISPs.
• Other benefits include enhancements relating to QoS, security, mobility, and multicast technologies.

Unlike IPv4, IPv6 does not use broadcasts. Instead, IPv6 uses the following methods for sending traffic from a source to one or more destinations:

• Unicast (one-to-one): Unicast support in IPv6 allows a single source to send traffic to a single destination, just as unicast functions in IPv4.
• Anycast (one-to-nearest): A group of interfaces belonging to nodes with similar characteristics (e.g., interfaces in replicated FTP servers) can be assigned an anycast address. When a host wants to reach one of those nodes, the host can send traffic to the anycast address and the node belonging to the anycast group that is closest to the sender will respond.
• Multicast (one-to-many): Like IPv4, IPv6 supports multicast addressing, where multiple nodes can join a multicast group. The sender sends traffic to the multicast IP address and all members of the multicast group receive the traffic.

The migration of an IPv4 network to an IPv6 network can take years because of the expenditures of upgrading equipment. Therefore, during the transition, IPv4-speaking devices and IPv6-speaking devices need to coexist on the same network. Consider the following solutions for maintaining both IPv4 and IPv6 devices in the network:

• Dual stack: Some systems (including Cisco routers) can simultaneously run both IPv4 and IPv6, allowing communication to both IPv4 and IPv6 devices.
• Tunneling: To send an IPv6 packet across a network that uses only IPv4, the IPv6 packet can be encapsulated and tunneled through the IPv4 network.
• Translation: A device, such as a Cisco router, could sit between an IPv4 network and an IPv6 network and translate between the two addressing formats.

IPv6 allows the use of static routing and supports specific dynamic routing protocols that are variations of the IPv4 routing protocols modified or redesigned to support IPv6:

Network Design Quiz

Related posts:.

Leave a Reply

Your email address will not be published. Required fields are marked *

White Papers

Ip address management best practices.

An IP addressing environment can quickly become a jungle (if it isn’t one already). However, you can impose rules, conventions, policies, and an overall plan to make your IP addressing simple- easy to understand, administer and grow, highly secure, always available, and lightning-fast.

Employ these best practice guidelines to make your IP Addressing Management (IPAM) run flawlessly and invisibly in the background throughout your network.

Download the white paper to learn how to make your network’s IP addressing environment manageable, flexible and secure:

• IP addressing based on business needs
• Define assignment rules
• Begin planning for IPv6
• Integrate IPAM with DNS and DHCP
• Monitor IP, DNS and DHCP for capacity planning

We use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.

We use cookies to enhance your browsing experience, serve personalized content, and analyze our traffic. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site.

10 IP Addressing Scheme Best Practices

IP addresses are a necessary part of any network, but there are best practices to follow to make sure they are used in the most effective way.

IP Addressing is a fundamental networking concept. It’s the process of assigning numerical labels to devices connected to a network. The purpose of IP Addressing is to uniquely identify devices on a network so that they can communicate with each other.

There are a few different IP Addressing schemes in use today, but the most common is the IPv4 scheme. This scheme uses a 32-bit address space, which allows for a total of 4,294,967,296 unique addresses.

While this may seem like a lot, the IPv4 address space is actually running out. This is due to the fact that the world population is growing and more and more devices are being connected to the internet. As a result, a new IP Addressing scheme, known as IPv6, is being slowly adopted.

IPv6 uses a 128-bit address space, which allows for a total of 340,282,366,920,938,463,463,374,607,431,768,211,456 unique addresses. This is a vast improvement over the IPv4 address space and will be able to accommodate the needs of the internet for many years to come.

When designing an IP Addressing scheme, there are a few best practices that should be followed in order to ensure that the scheme is effective and efficient.

1. Use a private IP address range

If you use a public IP address range, then your devices will be reachable from the Internet. This is not necessarily a bad thing, but it does open up your devices to potential attacks.

If you use a private IP address range, then your devices will only be reachable from within your own network. This is much more secure, as it means that anyone on the Internet will not be able to directly access your devices.

There are a few different private IP address ranges that you can choose from, but the most common one is the 192.168.0.0/16 range. This is the range that most home routers use, and it’s a good choice for small networks.

For larger networks, you may want to use a different private IP address range. The 10.0.0.0/8 range is often used for this purpose.

2. Assign static IP addresses to servers and network devices

If you don’t assign static IP addresses to your devices, then every time the device reboots it will be assigned a new IP address by the DHCP server. This can cause all sorts of problems, such as breaking firewall rules, disrupting network connectivity, and so on.

It’s much easier to manage a network when all of the devices have static IP addresses. You can easily add these devices to your inventory management system, and you’ll always know what IP address they are using.

There are some exceptions to this rule, such as when you’re using mobile devices that connect to the network via WiFi. In these cases, it’s usually best to use DHCP so that the devices will be automatically assigned an IP address when they connect to the network.

3. Use DHCP reservations for other hosts

When you use DHCP reservations, the IP address of a host is permanently assigned to that host, which means that the same IP address will always be assigned to that host as long as it’s on the network. This is useful for hosts that need to be accessible by other devices on the network using their IP address (e.g. servers, printers, etc.).

Using DHCP reservations also has the added benefit of making it easier to manage your IP addresses, since you don’t have to worry about manually assigning IP addresses to hosts or keeping track of which IP addresses are assigned to which hosts.

4. Avoid using the last IP in each subnet

When a device sends a broadcast, it sends it to all devices on the same subnet. The last IP in each subnet is reserved for broadcast, so if you use that IP as a host address, your device will receive its own broadcasts and process them, which can lead to all sorts of problems.

It’s much better to use the second-to-last IP in each subnet as your host address. That way, you’ll still be able to communicate with all devices on the subnet, but you won’t have to worry about processing your own broadcasts.

5. Don’t use broadcast or multicast addresses

Broadcast addresses are used to send data packets to all devices on a network. However, this can be a security risk because it means that any malicious actor on the network can intercept and read the data packets meant for other devices.

Multicast addresses are similar to broadcast addresses, but they’re used to send data packets to a group of devices rather than all devices on a network. While this is less of a security risk than using broadcast addresses, it can still be problematic because it can lead to network congestion if too many devices are receiving the multicast data packets.

6. Use VLANs to separate different types of traffic

VLANs are virtual LANs that can be used to segment traffic on a network. By separating different types of traffic onto different VLANs, you can improve security and performance while making it easier to manage your network.

For example, you might put all of your user traffic on one VLAN and all of your server traffic on another VLAN. This would make it much harder for an attacker to sniff traffic or launch a man-in-the-middle attack, and it would also make it easier to troubleshoot problems since you wouldn’t have to worry about cross-traffic affecting your results.

Additionally, using VLANs can help improve performance by reducing congestion on your network. For example, if you have a lot of video streaming traffic, you might want to put that traffic on its own VLAN so it doesn’t slow down other types of traffic.

Overall, using VLANs is a great way to improve the security and performance of your network while making it easier to manage.

7. Use NAT when connecting multiple networks

When you have multiple networks that need to communicate with each other, it’s important to use NAT (Network Address Translation) so that each network can have its own unique IP address range. This way, there won’t be any conflicts between the addresses of the different networks.

NAT also allows you to hide the internal IP addresses of your devices from the outside world. This is important for security because it makes it more difficult for hackers to target specific devices on your network.

Finally, NAT can help improve the performance of your network by reducing the number of broadcasts that are sent. Broadcasts are packets that are sent to all devices on a network, and they can cause problems if too many of them are sent. By using NAT, you can reduce the number of broadcasts that are sent, which can improve the performance of your network.

8. Use DNS names instead of IP addresses wherever possible

DNS names are much easier for humans to remember than IP addresses. They’re also less likely to change, which means that you won’t have to go through the hassle of updating your configuration files every time there’s a change in the IP address scheme.

What’s more, using DNS names instead of IP addresses can help improve security. That’s because it’s harder for attackers to guess DNS names than IP addresses.

Finally, using DNS names instead of IP addresses can help improve performance. That’s because DNS names are cached by DNS servers, which means that they don’t have to be resolved every time they’re used.

9. Document your IP addressing scheme

If you don’t document your IP addressing scheme, then when something goes wrong (and something always goes wrong), it will be very difficult for someone else to understand what you did and why you did it. This is especially true if the person who designed the scheme is no longer with the company.

Documenting your IP addressing scheme doesn’t have to be complicated. A simple spreadsheet that lists each subnet, the network address, the broadcast address, the netmask, and a description of what each subnet is used for is usually sufficient.

If you want to get really fancy, you can create a Visio diagram that shows how all of the subnets are interconnected. But even a simple spreadsheet will go a long way towards making sure that your IP addressing scheme is understandable and maintainable.

10. Keep it simple!

A simple IP addressing scheme is much easier to understand and manage than a complex one. When you have a large network with hundreds or even thousands of devices, it can be very difficult to keep track of all the different IP addresses and subnets.

It’s also important to keep your IP addressing scheme consistent across all your devices. This will make it much easier to configure and troubleshoot networking issues.

Finally, you should avoid using private IP addresses for public-facing services. Private IP addresses are not routable on the public Internet, so anyone trying to access your website or email server will not be able to reach it.

10 Git Repository Structure Best Practices

10 rest api file upload best practices, you may also be interested in..., 10 data lake folder structure best practices, 10 bitbucket repository structure best practices, 10 aws s3 folder structure best practices, 10 test case naming best practices.

Blog article

Static IP Vs. Dynamic IP: Usage And Differences

In this article, we weigh up static IP addresses vs. dynamic addresses, their differences and usage in business environments.

Lukas Dolnicek

‍ Every internet-enabled device has an IP address so that “IPs” play a crucial role in the interconnected world. In this article, we will weigh up static IP addresses vs. dynamic addresses and how to use them.

‍ The Internet Protocol (IP) enables communication over computer networks, a set of addressing and routing standards that ensure different devices can talk.

Before we dig deeper into what affects the usage of static and dynamic IP, let's explain the basic terms and what IP address is first.

• Internet protocol: A set of rules for how data travels across networks to arrive at the right designation.
• IP address : A unique code that gets assigned to a device each time it connects to the Internet.
• Local area network (LAN) : A computer network that connects devices to one another in a limited area. Examples would be areas such as a large office.
• Wide area network (WAN) : A communication network that extends over a large geographical area. The network is not limited to a single location.
• Dynamic host configuration protocol (DHCP) : A network server that automatically assigns IP addresses to devices.
• Network address translation (NAT) : A way to map multiple local private addresses to a public one before transferring any data.
• Ransomware attack : This is when a type of malware threatens to publish your business data online or blocks access to your data until you pay them ransom.

What Is an IP address?

An IP address is a numerical identifier assigned to devices communicating on a computer network (LAN, WAN, Internet).

An IP address is like your home address. It’s how you receive old-school snail mail, and it's where mail gets sent to you. Your residential address is unique and contains your location information, just like an IP address does.

It comprises four 8-digit binary numbers (0,1), for simplification presented in a decimal range of 0-255 separated by periods (example 192.168.2.1).

How are IP addresses assigned

An IP address is assigned to a host statically - selected by an administrator - or dynamically using DHCP service.

The best practice is to manually assign a static IP address to the device where continuous availability is critical. All the other devices should be assigned a dynamic IP address via DHCP.

Also, if you have employees who work remotely and need continuous access to your business systems, you would need a static IP address - which you can choose when you use a cloud VPN like GoodAccess .

What Does This Mean for Your Business?

Unique IP addresses are assigned to all devices connecting to a network like the Internet. They allow your devices to communicate with one another.

There are two types of IP addresses:

• Static IP addresses
• Dynamic IP addresses

What Is a Static IP Address

A static IP address, also called fixed IP address, is a numerical identifier that remains changeless indefinitely when assigned to a device. This is a unique number that remains unchanged for however long you need it—much like your home address.

It is used when it is undesirable to change the address dynamically, typically when permanent access is required (e.g., access to servers, routers, printers).

What This Means for Your Business:

You can use a static IP address to do something called IP whitelisting, which is when you only allow one static IP address - assigned to all your devices - to access your business network.

There are two main options on how to get a static IP address:

➡️ Leasing a static IP address

You can rent a static IP address from your Internet Service Provider.

➡️ Getting a static IP address from a VPN service

You can use business cloud VPN with dedicated static IP such as GoodAccess VPN Static IP service.

In this scenario, your users directly connect to a gateway and then to the desired network services. All the traffic after the gateway is with the same fixed IP.

Alternatively, your router can be configured to communicate to the Internet exclusively through the gateway, comprising all traffic under the same static IP (multiple hosts share one IP address). If you want to dig a bit deeper, see this article that explains how a modern IPsec VPN / VPN with static IP works.

You can either lease a static IP address from your ISP, or you can use one provided by a cloud VPN for businesses.

Using a static IP address along with a VPN allows you to control who can and cannot access your network.

How are static IP addresses used?

The most common static IP address use cases are restricting network access with IP whitelisting and enabling remote access (when you host a service inside your LAN and need to access it regardless of geographical constraints).

A static IP address is valuable to your business if you want to:

• Have a unique identification on the Internet and the possibility of IP whitelisting with no hassle.
• Avoid potential IP address conflicts WAN/LAN - the situation when two hosts are assigned with the same IP (which usually leads to one host being unable to communicate).
• Define firewall rules valid indefinitely (using a dynamic IP address would lead to updating the firewall rule every time the IP changes).
• Have your services hosted inside your LAN accessible from the public Internet.
• Have full responsibility for your IP reputation. Without a static IP, you use one of ISP’s shared dynamic IP addresses that don’t uniquely represent your network, and others might negatively affect your IP reputation. With Static IP, only you keep an eye on correct (r)DNS settings, IP reputation, correct IP geolocation and other parameters which is handy when you, ie. run an emailing service.

What Is a Dynamic IP Address?

A dynamic IP address is a numerical identifier assigned to a host (server, PC, laptop, mobile device, etc.) by DHCP ( Dynamic Host Configuration Protocol ) service to enable network communication.

In case you don't need a static IP for the particular device (typically smartphones, tablets, PCs) a dynamic IP address is an obvious choice.

Dynamic IPs will change based on your:

➡️ Location.

➡️ How long you have been connected to the Internet.

➡️ The different Wi-Fi networks you connect to.

The dynamic IP address is leased for a specified timeframe. After this period, the IP address becomes available to any other host that requests a new assignment (or a renewal) of an IP address - either when connecting to the network or after its previous IP lease time expired respectively (see figure 1).

So a different address can be assigned after this period (usually 24 hours, but this is a custom configuration) if the previous one is already in use by another host. This means that one host's address may change over time.

If your business devices have IP addresses that change, it becomes impossible to control which IP addresses can access your business systems and which cannot.

Pros and cons of using dynamic IP address:

• There is no need to restrict an IP address for any host on the network when not all hosts are connected simultaneously, so in theory, available IP range usage is optimized.
• Easy and automatic IP address assignment. If DHCP services are not used, each host would have to be manually assigned with a static IP address to communicate on the network. This is a time-consuming process, especially when the network scales. DHCP solves this problem by automatically assigning IP addresses.
• On the other hand, since a dynamic IP address doesn't represent an absolute unique identification of a device, network access control must be done using different means, such as Mac address, or better, user identity.

Static IP vs. Dynamic IP

Now that you know what each type of IP address involves, let’s compare the differences.

There is no simple answer to the question if it is better to have a static IP or dynamic IP.

Both have their significance, both enable network communication, but otherwise their purpose is different. Especially in a business environment.

If you are a common user, you probably don't care whether your IP address is static or dynamic (if you do, you can always check with Google, just type what's my IP address ).

But if your job is networking in a company, you care about the accessibility of the services and IP ranges, must deal with IP conflicts, and generally ensure smooth communication over the network, the distinction "dynamic IP vs static IP" is very important.

When it comes to running a business securely, there is no question as to which type of IP address would work best for you.

A static IP address protects your business from the outside world and any potential threats. It gives you control over who is allowed to access your business remotely and automatically rejects unauthorized addresses.

Although it may take time to assign a static IP address to each business device, it is worth the added effort when your business data is protected from prying eyes.

The best part is that you can quickly and easily get a static IP address from GoodAccess .

Wrapping Up on Static vs. Dynamic IP Addresses

Both static and dynamic IP addresses have their purpose and every responsible network administrator should follow best practices.

Sometimes, questions like whether static IP is safe or at least safer than dynamic IP address arise. From the server perspective, there is no relation between the security and the address type.

You are facing a potential danger no matter if your server has static or dynamic IP. What matters is correct firewall settings and access rights restriction.

A static IP address allows you to restrict access and ensure only the right people connect to your business network.

It gives your remote team the access they need to all your business systems while keeping your data completely private.

A dynamic IP address is more suited to situations where privacy is not the main priority.

When you subscribe to GoodAccess , you get your own static IP address that you can assign to all the devices within your business. This means you can keep your network and data private.

By using a static IP address with a cloud business VPN like GoodAccess, you keep your remote teams and your business safe from ever-increasing cyberattacks.

Frequently Asked Questions (FAQs)

How does dns help ip addresses.

When users access web services, IP addresses are translated into domain names by domain name system (DNS) servers to make things easier.

Thanks to DNS no one needs to type a series of numbers into the url and just type the name of the desired website they want to visit.

What is the difference between IPv4 vs IPv6?

Today, the most widely used IP version is IPv4, but the newer version IPv6 is increasingly more popular since it offers a much wider range of unique addresses thanks to its format.

The IPv6 format consists of eight groups of four hexadecimal digits separated by colons.

How do public IP addresses work?

In a LAN, devices inside this specific location are assigned a unique IP address manually or automatically by the dynamic host configuration protocol (DHCP) server.

These addresses are selected from a pool of internal IP addresses reserved for the internal LAN and are invisible to the outside world.

But this setup comes with a catch.

The local address is unique only in the specific location, but the same range is used in different LANs.

A device has to use a unique identifier to communicate via a network. A public IP address must be used when devices connect to the global Internet.

Network address translation (NAT) solves this problem by providing the device with a public IP address. Administrators can then choose whether a particular device needs a dynamic or static IP.

Let’s get started

SMEs are an increasingly popular target among cybercriminals because their limited resources prevent them from deploying security countermeasures. GoodAccess enables SMEs to deploy SaaS-based ZTNA to protect themselves against malware, man-in-the-middle, and other attacks.

release news

Release notes: Device Posture Check keeps non-compliant devices out of your perimeter while forced always-on connection ensures security measures are active at all times.

Remote work

A backup gateway provides redundancy in case an unexpected outage or performance issues impact the primary gateway. This ensures business continuity and reduces the cost of downtime.

In GoodAccess, we invest our passion into developing a cybersecurity platform that is easy to deploy, easy to manage, and easy to use.

Copyright ©2024 GoodAccess

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

What other IP addresses can/should I use for my home network?

I've been using 192.168.1.x for my home network, which has been perfectly happy for quite some time. However, I just started a new job, and they use the same set of IP addresses when I connect over the VPN.

Naturally, this causes problems.

What other IP address ranges can (and should) I use to prevent conflicts? Would it be OK to use 192.168.2.x ... or 42.x ;) ?

I know at one point my brother had setup our network to use 10.0.0.x - but when I used a traceroute program it would say that all of our packets were going to Brazil or something.

Are there other IP addresses reserved for internal networks that I should use?

• 1 I generally recommend that folks with home networks just use 192.168.XX.0/24 where XX is between 10 and 245. perhaps the last two digits of the year of your birth? Any number in that range works. "69 dudes!" -- Bill S Preston Esqr and "Ted" Theodore Logan –  Frank Thomas Commented Apr 24, 2015 at 12:50
• 17 @DavidGrinberg Hopefully, you'll never need to visit that range then. That range is assigned to a company called Xerox. –  phyrfox Commented Apr 24, 2015 at 14:25
• 11 If 10.0.0/24 traffic is going to Brazil, your ISP is doing something very weird, and you should call them out on it. Except with special arrangements between the parties involved, 10/8 (like the other RFC 1918 ranges) is supposed to never make it past the egress router of a network. –  user Commented Apr 24, 2015 at 17:17
• @MichaelKjörling, the exception is that as an ISP client, you are considered to be part of their private network. So, if the ISP's network spans internationally (such as Brazil) you can potentially reach a 10.0.0.0/8 address in another country. While it is generally good design to minimize this exposure to clients, this is an increasing trend as ISPs run out of PI IP space to use on their internal networks. –  YLearn Commented Apr 24, 2015 at 18:14
• Very weird IMO for your company to be using 192. 172 or 10 are typical in companies with any kind of knowledgeable IT department. –  crthompson Commented Apr 24, 2015 at 22:22

5 Answers 5

You can freely use any Private Network Address within the following reserved ranges:

Private Address Space The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets: 10.0.0.0 - 10.255.255.255 (10/8 prefix) 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

(from RFC 1918 - Address Allocation for Private Internets )

You'll also want to keep in mind the network Host Address and Broadcast Address :

Broadcast IP Addressing - Proposed Standards If different IP implementations are to be compatible, there must be a distinguished number to denote "all hosts". Since the local network layer can always map an IP address into data link layer address, the choice of an IP "broadcast host number" is somewhat arbitrary. For simplicity, it should be one not likely to be assigned to a real host. The number whose bits are all ones has this property; this assignment was first proposed in. In the few cases where a host has been assigned an address with a host-number part of all ones, it does not seem onerous to require renumbering. The address 255.255.255.255 denotes a broadcast on a local hardware network, which must not be forwarded. This address may be used, for example, by hosts that do not know their network number and are asking some server for it. Thus, a host on net 36, for example, may: broadcast to all of its immediate neighbors by using 255.255.255.255 broadcast to all of net 36 by using 36.255.255.255 (Note that unless the network has been broken up into subnets, these two methods have identical effects.) If the use of "all ones" in a field of an IP address means "broadcast", using "all zeros" could be viewed as meaning "unspecified". There is probably no reason for such addresses to appear anywhere but as the source address of an ICMP Information Request datagram. However, as a notational convention, we refer to networks (as opposed to hosts) by using addresses with zero fields. For example, 36.0.0.0 means "network number 36" while 36.255.255.255 means "all hosts on network number 36".

(from RFC 919 - Broadcasting Internet Addresses )

Additionally, you'll want to understand Classless Inter-Domain Routing (commonly referred to as CIDR) and its CIDR notation for expressing IP address ranges:

Classless Inter-Domain Routing (CIDR, /ˈsaɪdər/ or /ˈsɪdər/) is a method for allocating IP addresses and IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous addressing architecture of classful network design in the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses.

CIDR notation is a compact representation of an IP address and its associated routing prefix. The notation is constructed from an IP address, a slash ('/') character, and a decimal number. The address may denote a single, distinct interface address or the beginning address of an entire network. The maximum size of the network is given by the number of addresses that are possible with the remaining, least-significant bits below the prefix. The aggregation of these bits is often called the host identifier. For example: 192.168.100.14/24 represents the IPv4 address 192.168.100.14 and its associated routing prefix 192.168.100.0, or equivalently, its subnet mask 255.255.255.0, which has 24 leading 1-bits. the IPv4 block 192.168.100.0/22 represents the 1024 IPv4 addresses from 192.168.100.0 to 192.168.103.255. the IPv6 block 2001:db8::/48 represents the block of IPv6 addresses from 2001:db8:0:0:0:0:0:0 to 2001:db8:0:ffff:ffff:ffff:ffff:ffff. ::1/128 represents the IPv6 loopback address. Its prefix length is 128 which is the number of bits in the address.

• 4 yes you put that well, though dot 0 is the network address, and dot 255 the broadcast which he may use but he wouldn't assign. –  barlop Commented Apr 24, 2015 at 14:01
• 6 @barlop Addresses ending in .0 and .255 do not indicate the network and broadcast addresses respectively, except in the very specific case where the IPv4 subnetwork ("subnet") mask is exactly 24 bits long. 24-bit netmask length (netmask 255.255.255.0) is a common setup for private networks, but it is not necessary and in fact "classful" IP address assignment has been deprecated since the mid-1990s. These days all IPv4 assignments are CIDR . –  user Commented Apr 24, 2015 at 17:14
• 2 Note: the "private networks" above refers to private residential networks. (Grace period ran out and I'd rather not delete the comment now.) Corporate networks may very well require a shorter netmask to accomodate all the hosts that need to be on a given subnet. –  user Commented Apr 24, 2015 at 17:19
• 4 @barlop the point is that your statement above is misleading. Take 192.168.0.0/23 for example. Your statement above would lead someone to think that 192.168.0.255 would be the broadcast address when this is a valid host address and the broadcast address is actually 192.168.1.255. Similarly, 192.168.1.0 is not a network address but a valid host address. The only time a .0 is always a network address and a .255 is always a broadcast address is a /24. –  YLearn Commented Apr 24, 2015 at 18:17
• 2 @barlop A smaller-than-/24 is the common globally-routable assignment for leaf sites these days. 10+ years ago I administered two separate IPv4 networks which had been assigned globally routable IPv4 addresses, one /27 and one /28 (same ISP, same customer, different sites). The public netblock at my current workplace is similar; I don't recall exactly, but I think it's a /28. Your initial comment said that "dot 0 is the network address, and dot 255 the broadcast", which holds if and only if the netmask is /24. For any other case, the statement is either (a) misleading or (b) outright false. –  user Commented Apr 24, 2015 at 18:39

The 192.168.1.1 IP address used by many home routers is an IANA-reserved private network address or subnet .

What's a subnet? An entire range of IP addresses that you can split up into a smaller ranger (the act of splitting it up is called subnetting) if you want.

So the above range is 192.168.0.0/16. Keeping it simple without getting too much into the individual bits, each "octet" or individual number in the address is 8 bits, and the ones that are "yours" start from the right. So that means the last two octets (16 bits) are yours to do whatever you want. So you can use all the IP addresses from 192.168.0.1 to 192.168.255.254 (the first one is reserved and the last one is a broadcast address) really in any way you want and your router allows.

The simplest route usually taken in this situation is to use the "sub-subnet" 192.168.0.0/24 or 192.168.1.0/24. Using 192.168.0.0/24 as an example, this means your home network can use any IP address from 192.168.0.1 through 192.168.0.254, with 192.168.0.255 being the broadcast address.

But you are free to change the subnet, since you have two numbers that are really "yours", so you can use 192.168.44.0/24 or any other number for the second octet. Just keep in mind that everything that needs to see each other on the network needs to be on the same subnet (i.e. within that subnet's range of IP addresses). So your router's IP address needs to appear in that subnet (good choice is 192.168.44.1), and your router needs to give out DHCP addresses from a range in that subnet (say something like 192.168.44.10 through 192.168.44.50).

Nothing is really stopping you from using 192.168.0.0/16 for your home router either, but it's good practice to leave some room for additional networks or changing things in the future.

• 1 I would say this is the should and @FranciscoTapia is the can [of the answers title can/should] –  Austin T French Commented Apr 24, 2015 at 13:21
• @AthomSfere i think you are absolutly right. –  Francisco Tapia Commented Apr 24, 2015 at 14:05
• 2 You've got the subnet mask lengths backwards. /8 gives you 24 bits host . You want /24 which gives you 8 bits host (32 total minus 8 and 24 for network, respectively). 192.168/16 is RFC 1918 space, anything less (longer subnet mask) which fully fits within that range is thus also 1918 space. –  user Commented Apr 24, 2015 at 17:25
• Thanks for pointing out the total derp on my part, fixed. –  LawrenceC Commented Apr 24, 2015 at 19:20
• @AthomSfere Can you elaborate on why this is the "should"? –  Jon Bentley Commented May 8, 2015 at 12:20

Yes, you would be OK using .2.x, and that would not cause any problems, however make sure your netmask is set to 255.255.255.0 and not 255.255.0.0 because it would try to mix your .2.x with your vpn .1.x as if it was the same network.

I know this is an old question, and some answers above are correct.

To put it simply, the Internet Assigned Numbers Authority (IANA) established three blocks of the IP address space for private networks:10.0.0.0 – 10.255.255.255, 172.16.00 – 172.31.255.255, 192.168.0.0 – 192.168.255.255.

The third IP address that you used is enough for most users for connecting up to 254 devices. So it have been commonly used till today.

Note that there is really nothing wrong from using a 10.0.0.0 or 172.16.00.

• 2 The third IP address that you used is enough for most users for connecting up to 254 devices . Not quite. It is enough for a lot more devices. (2^16-2, aka 65534 devices, not just 2^8-2 aka 254). –  Hennes Commented Jul 22, 2016 at 9:17

The reason why you should use private addresses in those ranges in your internal networks, is because these are the addresses that are not used on the internet for real networks.

In fact backbone routers won't forward in general packets for these addresses (although some ISPs actually dish out private IPs to customers, in this case you'll be going through their NAT).

If you choose another range of addresses for your network, which are public addresses, in use somewhere else in the internet, then you lose accessibility to those other addresses, due to local routes to those destinations overriding default routing to the real remote network.

• Correct. You can do that just fine, but you need to make sure those IPs belong to you (and by that also not to someone else on the Internet). That used to be the way that the Internet worked before we ran out if IPv4 addresses. These days home users are forced to use NAT, and thus RFC1918 or some clever routing and loose access to a few devices on the Internet. –  Hennes Commented Jul 22, 2016 at 9:21
• I hate to think how many people can't access the 1.2.3.0 network over the internet. We saw a lot of customers use this range over the years on their internal networks. –  Adrien Commented Jul 22, 2016 at 9:26
• Not as bad as seeing a network using the loopback address range, in two different locations. Now mind you this was all OLD ethernet, the network used hubs, not switches to connect everyone. Actually the Hubs were only used for the 10BaseT computers, the 10Base2/5 machines had their own ring,. And Hubs are dumb! They did not care what your IP address was and neither did the Windows of the time. I got called in, when they tried to connect them via Frame Relay. and it would not route properly. –  GB - AE7OO Commented Jan 10, 2020 at 14:21

You must log in to answer this question.

Not the answer you're looking for browse other questions tagged networking vpn ..

• Featured on Meta
• Announcing a change to the data-dump process
• We've made changes to our Terms of Service & Privacy Policy - July 2024

Hot Network Questions

• Why do repeating 8's show up more often in these decimals of square roots?
• Why are the Founders in Star Trek: Deep Space Nine considered so powerful?
• What would the correct answer be for Mendelson Exercise 1.4 (g)
• Split column into lines using awk
• Absolute invisibility in cosmos
• What does ボール運び mean, exactly? Is it only used in basketball?
• Why do doctors always seem to overcharge for services?
• Why would radio-capable transhumans still vocalise to each-other?
• The 'correct' way to draw a diagram
• What acceleration features did 2D PC video cards have? Comparing to video game consoles
• How to extract pipe remnant from ground sleeve?
• How to design a resampling filter?
• Where is there is only set of odds ratio in ordinal logistic regression?
• F-test for nested GLM
• Could mage hand be used for surgery on another creature?
• Screenshot of the Launchpad?
• Can I travel to Malaysia from Singapore?
• Was the idea of foxes with many tails invented in anime, or is it a Japanese folk religion thing?
• Why is transfer of heat very slow as compared to transfer of sound in solids?
• What are the specific terms for breaking up English words into roots/components
• How should Psalm 5:3 אֶֽעֱרָךְ־ best be translated
• On how to produce videos like this one
• How can DC charge a capacitor?
• Can you be resurrected while your soul is under the effect of Magic Jar?

• Dedicated Servers

Allocating IP Addresses: 7 Best Practices for 2024

• January 31, 2024
• - 2 mins read

Try this guide with our instant dedicated server for as low as 40 Euros

By providing your email address, you agree to our Terms of Service and that you have reviewed our Privacy Policy .

• Key Takeaways
• An IP address is a unique set of characters identifying every device using the Internet to communicate over a network.
• IP addresses are important for enabling communication over the Internet, security, location tracking, etc.
• IPv4 is the original Internet protocol used since the 1980s.
• IPv6 is a 128-bit address system developed to address IPv4 exhaustion.
• IP addresses are assigned either dynamically by a DHCP server, which allocates them as devices connected to a network, or statically, where a network administrator manually sets them.
• Best practices for IP address allocation include planning an IP address scheme, using subnetting, implementing Dynamic Host Configuration Protocol, having a record, etc.
• Types of IP addresses include Consumer IP addresses, Private IP addresses, Public IP addresses, etc.
• Two types of website IP addresses include shared IP addresses and dedicated IP addresses.
• When deciding between shared vs dedicated IP address, factors include SEO, security, budget, and site traffic.
• Strategies to protect your IP address include using a VPN, enabling private browsing, using public Wi-Fi with caution, etc.

With abundant new devices connecting to the internet daily, efficient IP address allocation has become critical today. According to a report, there are nearly 17.08 billion connected IoT devices in 2023. This noteworthy number shows the need for effective IP address management strategies.

Proper allocation of IP addresses is more than just a matter of operational convenience. It is critical for ensuring smooth connectivity, security, and scalability in any network infrastructure. This blog takes readers through the best practices for allocating IP addresses.

Table Of Contents

• What is an IP Address?

Enables Communication Over the Internet

Identifies devices, facilitates location tracking and customization, helps in network organization and management.

What Does IPv4 Do?

Why is IPv4 Important?

The Limitation of IPv4

How IPv4 Works in Everyday Life

Why Do We Need IPv6?

The Importance of IPv6

Challenges in Adopting IPv6

IPv6 and Everyday Internet Use

Connecting to a Network

DHCP Server Response

For Static IPs

For Public IPs

Plan Your IP Address Scheme

Use Subnetting

Implement Dynamic Host Configuration Protocol (DHCP)

Maintain a Record

Implement IP Address Management (IPAM) Tools

Regularly Review and Optimize Your IP Address Scheme

Follow Security Best Practices

Depletion of IPv4 Addresses

Efficient IP Address Management

Addressing Security Concerns

Compatibility and Transition Challenges

Dynamic IP Address Allocation Issues

Consumer IP Addresses

Private IP Addresses

Public IP Addresses

Dynamic IP Addresses

Static IP Addresses

Shared IP Address

Dedicated IP Address

Website Traffic and Resources

Security Needs

Use a Virtual Private Network (VPN)

Employ a Proxy Server

Enable Private Browsing

Use Public Wi-Fi (With Caution)

Consider Using TOR

Consider Using a Secure ISP

Regularly Change Your IP Address

Understanding Dedicated Servers

Key Characteristics of Dedicated Servers

The Role of Dedicated Servers in IP Allocation

What is an IP Address ?

Credits: FreePik

An IP address (Internet Protocol address) is like a home address but for your computer or device on the Internet. It’s a unique set of numbers separated by periods, like 192.168.1.1. This helps identify each device connected to the Internet.

Just as your home address lets people send you mail, an IP address lets computers send and receive information from other computers. It’s essential because it ensures that when you go online and ask to visit a website or send an email, the Internet knows where to send the website’s data or where the email needs to go.

There are two types of IP addresses. The first is IPv4, the traditional format with around four billion addresses. The second type is IPv6, a newer format created to provide many addresses as the Internet grew and more devices needed unique addresses. An IP address is an important aspect of how the Internet works, acting to identify and locate billions of devices on the vast Internet network.

Are you struggling to find your IP address in Linux? Read our informative piece, ‘ How To Find Your IP Address In Linux | 4 Easy Ways ,’ for answers.

What is the Importance of IP Address ?

The importance of an IP address in the digital world is multi-faceted and extends beyond the basic functionality of enabling internet connectivity. Below are factors to help you understand its significance:

An IP address acts like a digital postman. Imagine you’re sending a letter. You need the correct address to reach the right person. Similarly, when you’re online and want to send an email or visit a website, your device requires the correct IP address of the recipient or website.

This address ensures your email reaches the right inbox or lands on the correct website. The internet could not function without IP addresses, as there would be no way to direct information to its proper destination.

The IP address is your device’s identity on the internet. Similar to how your fingerprint identifies you, your device’s IP address identifies it on the internet. This unique identification is critical, especially today, where countless devices are connected to the internet. It ensures that when you request information or a service online, your device receives it, not someone else’s.

Have you ever wondered how websites know what language to display or why some online services are unavailable in your region? This is where IP addresses come in. They provide an approximate location of where your device is accessing the internet.

This location-specific data is used by websites to edit their content, like showing you news relevant to your area or items that can be shipped to your location. This customization improves your online experience by making it more relevant.

IP addresses are critical for online security. They can be used to track down devices involved in malicious activities. For instance, if a specific IP address is consistently involved in cyber attacks or spamming, it can be blocked by websites or internet service providers, acting as a defense against cyber threats. Monitoring IP addresses also helps pinpoint unusual patterns that could signal security breaches.

IP addresses are crucial for network organization in multiple-device environments. Some examples include corporate offices or university campuses. They enable network administrators to find and manage devices on the network easily.

If a specific computer is causing network issues, the administrator can use its IP address to locate and address the problem. In setting up networks, assigning IP addresses to each device helps organize the network systematically, ensuring smooth operation and easy troubleshooting.

Also Read: Learn About IP Addressing Schemes And Subnet Masks .

What is IPv4?

Credits: Freepik

IPv4 stands for Internet Protocol version 4. It’s slightly comparable to postal service of the Internet, a set of rules that helps direct data to the right place. An IPv4 address is made up of four numbers separated by dots.

For instance, an IPv4 address might look like this: 189.168.1.1. Every number set can range from 0 to 255. This format offers many possible combinations. It still does have a limit on how many addresses it can form.

IPv4 is a specific version of this Internet Protocol. It’s responsible for identifying devices on a network and routing data between them. Every device linked to the Internet requires its own IP address, a series of numbers that identifies that specific device. IPv4 creates these addresses.

IPv4 is important because it’s one of the main protocols for the Internet. Sending and receiving data over the Internet would be chaotic and disorganized without IPv4. It can be compared to having a mail system without addresses or postal codes.

One issue with IPv4 is that it can only create about 4 billion unique IP addresses. This may sound like a lot, but we are running out of these addresses due to the high number of devices linking to the Internet. This limitation has led to the development of a new version called IPv6. This version can create a much larger number of addresses.

IPv4 is operational in the background whenever you visit a site, play a video, or send an email. It directs the data you send and receives to the right devices. Whether using Wi-Fi at home or data on your phone, IPv4 keeps you linked to the online space.

Also Read: Add Additional IPv4 Addresses on Windows Server 2019 in 4 Simple Steps

What is IPv6?

IPv6 stands for Internet Protocol version 6. It’s the newest Internet Protocol version. IPv6 was developed to replace IPv4, the previous version, which has existed since the Internet’s early days.

The main reason for IPv6 is the need for more IP addresses. Think of it like phone numbers. We need more unique phone numbers as more people get phones. Similarly, we need more unique IP addresses as more and more devices link to the Internet.

IPv4, a 32-bit addressing scheme, can support about 4.3 billion addresses. That sounds like a lot, but we’ve already run out of them. IPv6, with its 128-bit addressing, can support a greater number – 340 undecillion addresses.

IPv6 addresses is important because of the enormous amount of IP addresses it can generate. This means we’re unlikely to run out of IP addresses anytime soon. IPv6 allows internet data to be routed more efficiently. This can lead to quicker and more reliable internet connections.

IPv6 was also designed with a focus on security. It has built-in features for encrypting data and ensuring data packets are authentic, which is not standard in IPv4. With IPv6, devices can automatically configure themselves when connected to an IPv6 network, thanks to a process called address auto-configuration.

The adoption of IPv6 has been slow despite its many benefits. One reason is the sheer scale of replacing or upgrading countless internet-connected devices and systems to be IPv6 compatible. Since IPv4 and IPv6 aren’t directly compatible, running them side-by-side can be complex.

The transition to IPv6 won’t be noticeable for most Internet users. It’s more of a behind-the-scenes change. It’s a necessary evolution to ensure that the Internet can keep growing and adding new devices. Over time, more websites and online services will transition to IPv6. This transition is gradual, and many systems now use both IPv4 and IPv6.

Also Read: Dedicated IP Vs Shared IP: Differences, Benefits & Their Impact .

How are IP Addresses Assigned?

Connecting to the internet is similar to getting an entry ticket at an event. Each ticket (or IP address) lets you access the event (or network). Here is how this “ticketing” process works when devices connect to a network:

Imagine entering a Wi-Fi network like walking into a cafe with free Wi-Fi. When you enter (connect), you ask for a ticket to use their service.

• Requesting an IP Address : As soon as your device connects to the network, it looks for an IP address. This is like asking the cafe staff for a Wi-Fi code.

Most home and office networks have a DHCP (Dynamic Host Configuration Protocol) server. This is usually part of your router.

• Assigning an IP Address : The DHCP server listens to your device’s request and gives it an IP address. This address is usually temporary (dynamic). It’s like the cafe staff giving you a Wi-Fi code that changes daily.

Sometimes, a device needs a special, unchanging IP address. This is called a static IP address.

• Setting Up a Static IP : An IT professional can manually set this up on your device. Once set, this IP address doesn’t change, even if you disconnect and reconnect to the network. It’s similar to having a VIP pass to the cafe, where you have a special code that consistently works just for you.

Things are slightly different when it comes to accessing the broader internet. Your Internet Service Provider plays a significant role here.

• ISP Assigning Public IPs : The ISP has several IP addresses, like a stack of tickets. When your home or business network connects to the internet, the ISP gives your network a public IP address. This address represents your entire home or business on the internet. It’s like the cafe having its unique address in the city.

Best Practices for Allocating IP Addresses

IP address allocation is an important aspect of network management. It involves assigning unique identifiers to each device within a network, ensuring efficient communication and management.

IP address allocation can become chaotic without proper planning and practices. This can lead to IP conflicts and network inefficiency. This makes it critical for one to follow IP address allocation best practices. Here are a few best practices for allocating IP addresses:

• Understand Your Network’s Size and Scope : Assess the number of devices that will be connected to your network. This understanding will help guide your IP address allocation strategy.
• Choose Between IPv4 and IPv6 : IPv4 is the most commonly used IP version but has few addresses. IPv6 offers a much larger address space. Choose the appropriate version depending on your network’s size and future growth.

Subnetting is dividing a network into smaller, manageable parts (subnets). This makes network management more efficient and improves security.

• Organize Network into Subnets : Divide your network logically based on departments, usage types, or geographical locations.
• Allocate IP Addresses to Subnets : Assign each subnet a range of IP addresses. Doing so helps in managing traffic and improving security.

A subnet calculator can be an invaluable tool here. It helps you divide your network logically and allocate IP ranges accordingly.

Why Use a Subnet Calculator ?

• Efficiency : It automates the calculation process, reducing errors.
• Optimization : Helps in optimal utilization of IP address space.
• Simplification : A subnet calculator makes subnetting more accessible, especially for complex networks.

DHCP automatically allocates IP addresses to devices on a network. This automation reduces the chances of IP conflicts and eases the management burden.

• Configure DHCP Server : Set up a DHCP server to manage and automate the IP address allocation process.
• Reserve IP Addresses : For critical devices like servers and printers, reserve static IP addresses to ensure they always receive the same IP.

A detailed record of IP address allocations is essential for troubleshooting and managing the network effectively.

• Document IP Addresses : Maintain an up-to-date record of all allocated IP addresses, including static and dynamic assignments.
• Regularly Update Records : Whenever a change is made in the network or a new device is added, update the documentation accordingly.

Also Read: How To Assign Floating IP In Leaseweb With Your Subnet In New Ways .

IPAM tools can automate many aspects of IP address management, making the process more efficient and less prone to errors.

• Choose an IPAM Solution : Select a tool that suits your network’s size and complexity.
• Integrate IPAM with Your Network : Ensure your IPAM tool fully integrates with your network infrastructure for optimal performance.

The network needs to evolve with time. Regularly review your IP address allocations to meet your network’s needs. Always be prepared to restructure your IP addressing scheme to adapt to changes in your network.

Securing your IP addresses is crucial to protect your network from threats.

• Use Private IP Addresses for Internal Network : Use private IP ranges for devices within your network to enhance security.
• Implement Firewalls and Network Segmentation : Use firewalls to control traffic and segment your network to contain potential breaches.

Challenges in IP Address Allocation and their Solutions

IP address allocation has its challenges. Below, we explore some of the top challenges linked to IP address allocation and their solutions.

IPv4 addresses are limited to approximately 4.3 billion unique combinations. This number seemed plentiful when the Internet came about. However, the exponential growth in Internet users and the addition of smart devices and IoT (Internet of Things) changed this. It brought us to a situation where the availability of new IPv4 addresses became critically low.

Regional Variations

The rate of IPv4 exhaustion varies globally. Some regions have already drained their allotment, while others are quickly approaching this point. This difference can cause operational challenges and inequities in internet accessibility and growth potential across various geographical areas.

Solutions for IPv4 Depletion

Let’s discuss some possible solutions to IPv4 Problems.

Adoption of IPv6

IPv6 addresses this limitation with its 128-bit address space. It offers around 340 undecillion unique IP addresses. This enormous capacity is more than sufficient to accommodate future growth.

• Gradual Transition : The shift to IPv6 isn’t instantaneous. It requires strategic planning and investment in IPv6-compatible hardware and software.
• Benefits : IPv6 offers enhanced security features and more efficient routing besides addressing depletion.

IP Address Sharing

Network Address Translation is important in mitigating IPv4 depletion. It enables multiple devices in a private network to share the same public IPv4 address.

• Types of NAT : Solutions like Port Address Translation enable multiple internal requests to be translated into a single IP address with varying port numbers.
• Limitations : Although NAT helps conserve IP addresses, it can complicate network configurations and restrain certain services, like peer-to-peer applications.

Efficient management of existing IP addresses becomes necessary as we navigate the challenges of IPv4 depletion.

IP Address Management (IPAM) Tools

These tools offer a centralized platform for locating and managing IP addresses, ensuring optimal resource use.

• Features : Advanced IPAM solutions offer automated address allocation, real-time tracking, and detailed reporting.
• Integration with DHCP and DNS : Effective integration with Dynamic Host Configuration Protocol and Domain Name System management is essential for streamlined operations.

With the growing complexity of IP address allocation, security risks also escalate.

Enhancing Security Measures

Implementing vigorous security protocols is critical to protect against IP spoofing and hijacking dangers.

• Access Control : Implementing stringent access controls and authentication mechanisms for accessing IPAM tools and network configurations.
• Regular Audits and Monitoring : Continuous monitoring for unusual activities and routine audits of IP address allocations are essential in specifying and mitigating potential security threats.

The transition from IPv4 to IPv6 is a necessary evolution in internet technology. It is, however, not without its challenges, especially regarding compatibility and infrastructure readiness. Let’s discuss these challenges and the solutions to facilitate a smoother transition.

The Complexity of Transitioning

• Technical Incompatibility: IPv4 and IPv6 are incompatible. This means devices and services created for IPv4 cannot communicate with those developed for IPv6. This is a major challenge in terms of maintaining connectivity and services during the transition period.
• Legacy Systems: Many organizations have legacy systems and infrastructure that only support IPv4. Upgrading or changing these systems can be expensive and complex. It may demand considerable planning and resources.

Solutions for Transition Challenges

Let’s discuss some possible solutions for Transition Challenges.

Dual Stacking

Dual stacking involves running IPv4 and IPv6 simultaneously on the same network. This approach allows for a gradual transition by maintaining compatibility with both protocols during migration.

• Operational Flexibility : It offers flexibility, allowing network administrators to manage the transition at a pace that suits their organization’s needs.
• Challenges : Running two protocols requires careful configuration to avoid complexities and potential security vulnerabilities.

Upgrading Infrastructure

Investing in new infrastructure is critical for a complete transition to IPv6. This includes upgrading routers, switches, and servers to support IPv6 natively.

• Long-Term Investment : Although the initial cost can be high, this is a long-term investment in the network’s future scalability and security.
• Vendor Support : Choosing vendors and solutions that offer robust IPv6 support is crucial.

Want to learn more about IPv4 and IPv6? Read our blog, ‘ Evolving Internet Protocols: IPV4 Vs IPV6 Compared .

While efficient, the dynamic allocation of IP addresses introduces its own challenges.

Problems with Dynamic Allocation

• IP Conflicts and Connectivity Issues: Dynamic allocation can sometimes lead to IP conflicts, where two devices are inadvertently assigned the same IP address, leading to connectivity issues.
• Managing a Fluid Network Environment: Managing a constantly changing set of IP addresses can be challenging in dynamic environments, especially with mobile devices and IoT.

Solutions for Dynamic Allocation

Now Let’s discuss some possible solutions for Dynamic Allocation.

Dynamic Host Configuration Protocol (DHCP)

DHCP is a network management protocol that automates the assignment of IP addresses.

• Efficient Management : DHCP servers assign IP addresses for a specific lease time, ensuring efficient use of an IP address pool.
• Flexibility : DHCP allows for easy reconfiguration of IP settings on the network without manual intervention.

Lease Time Management

Proper management of DHCP lease times is essential in dynamic environments.

• Optimizing Lease Times : Setting appropriate lease times can reduce the likelihood of IP conflicts and address exhaustion.
• Adapting to Network Needs : Lease times can be adjusted based on the network’s specific needs, such as shorter leases for guest networks.

Types of IP Addresses

There are different types of IP addresses. Each serves a specific purpose. It is important to understand each IP address, its role, functionalities, etc. Here is an in-depth breakdown of the different types of IP addresses:

Consumer IP addresses are IP addresses usually assigned to individuals or households by Internet Service Providers. These addresses are used for personal internet access. Consumer IPs can be dynamic or static (discussed below). The key feature of consumer IP addresses is that they are allocated for standard, non-commercial internet usage, like browsing, streaming, or gaming.

Private IP addresses are used in a private network. They are not visible on the public internet. These are the addresses your home or office router assigns to each device on your local network. Examples include your computer, smartphone, or printer. Private IP addresses allow multiple devices in the same network to communicate.

The range of private IP addresses is defined in the IPv4 and IPv6 standards and cannot be routed through the public internet. This makes private IPs ideal for internal network security and efficiency.

Public IP addresses are used globally and must be unique across the entire internet. These are the addresses that ISPs assign to each of their customers. When you open a website, your public IP address is how the website knows where to send the data. Public IP addresses are essential for external communication over the internet. They enable different networks worldwide to connect and interact.

Dynamic IP addresses are temporary. They are assigned to a device each time it connects to the network. A Dynamic Host Configuration Protocol server within the network typically manages and distributes these addresses. This includes your router or ISP.

A standout advantage of dynamic IPs is their efficiency in reusing addresses. They are ideal for consumer and business networks where devices frequently come and go. This is because they eliminate the need for manual IP configuration and reduce the risk of IP address conflicts.

Static IP addresses are fixed. They do not change over time. These addresses are manually assigned to a device and remain constant until changed manually. Static IPs are beneficial when a device needs a constant address. For instance, a server hosting a website or a remote access system.

They provide reliable and consistent remote access. This makes them ideal for businesses with fixed network infrastructure. However, static IPs require more management and are more likely to experience security risks if not properly secured. This is because their constant nature can make them easier targets for malicious activities.

What are The Two Types of Website IP Addresses

Credits: Pexels

Website IP addresses come in two main types: shared and dedicated. Both have their unique characteristics, advantages, and drawbacks. Here is more information on the two types of website IP addresses:

A shared IP address refers to an IP address used by numerous websites or domains. This setup involves a server hosting several websites with the same IP address. This is a common practice in web hosting, especially in shared hosting environments where multiple clients’ websites are hosted on the same server infrastructure.

How Shared IP Addresses Work

Here’s how shared IP addresses work:

• Hosting Structure : Multiple websites are hosted on a single server. They share the server’s resources.
• Traffic Routing : The server uses the same IP address to route traffic to all these websites. The HTTP/HTTPS header contains the domain name. This tells the server which website the user is trying to access.
• Domain Name Resolution : The server’s software, like Apache , reads the request and serves the appropriate website content based on the domain name.

Shared IP addresses offer several advantages in various network and web hosting scenarios:

• Cost-Effective : Shared IP addresses are generally more affordable. This makes them best for small businesses or personal websites with limited budgets.
• Easy to Manage : Shared IPs offer a seamless experience. This is mainly because the hosting provider handles the technical aspects. This includes server maintenance and software updates.
• Reduced Complexity for Small-Scale Deployments: Shared IP addresses offer a simplified setup. This is ideal for individuals or small businesses with basic website requirements. The setup eliminates the need for complex network configurations.

Disadvantages

While shared IP addresses offer advantages, they also come with some disadvantages:

• Neighbor Effect : If one website on a shared server is blacklisted by search engines or flagged for spamming, it can negatively impact all other websites sharing the IP. This is because the IP address’s reputation affects all associated domains.
• Limited Control and Customization : Users have less control over server settings and resources. For instance, installing specific software or performing custom server configurations is often not possible.
• Small business websites with limited traffic.
• Personal blogs or portfolio websites.
• Startups looking for cost-effective hosting solutions.
• Websites without the need for SSL certificates for online transactions.
• Users with basic hosting needs and minimal technical expertise.

Also Read: Your Ultimate Cheat Sheet To IP Transit .

A dedicated IP address is a distinctive Internet Protocol address exclusively assigned to a single hosting account or website, offering higher control and stability. This exclusivity distinguishes it from shared IP addresses, where multiple websites use one IP.

How Dedicated IP Addresses Work

Here’s how dedicated IP addresses work:

• Unique Assignment : Each website or hosting account is assigned a unique IP address.
• Hosting Flexibility : While typically associated with dedicated servers, a dedicated IP can also be used in a shared hosting environment, providing a unique identity to a website on a shared server.
• Direct Access : Websites with a dedicated IP can be accessed directly via the IP address, facilitating specific tasks and setups.

Dedicated IP addresses offer several advantages in various network and hosting scenarios:

• Improved Performance and Security : Being the sole occupant of an IP address means the site’s performance isn’t affected by other sites’ traffic and usage patterns. Dedicated IPs also reduce the risk of IP blacklisting due to other websites’ malpractices.
• Required for Certain Applications ( SSL Certificates) : Essential for websites that handle sensitive transactions, such as e-commerce sites. A dedicated IP facilitates the installation of these certificates.
• Greater Control : Dedicated IPs enable more control over DNS settings. This is important for larger websites or those with specific technical requirements. They also allow for more advanced server configuration and customization options.

Despite the advantages, dedicated IP addresses also come with some disadvantages:

• Higher Expense : Dedicated IPs come with additional costs. They also often require more expensive hosting plans with dedicated IP functionality. This can be major drawback for small businesses or individual users.
• Technical Knowledge : Dedicated IPs require more technical expertise to manage and configure. Users also need to be more involved in server administration. This may be stressful for those lacking technical backgrounds.
• E-commerce websites requiring SSL certificates for secure transactions.
• Large corporate sites with high traffic volumes.
• Websites needing specific server customizations.
• Services requiring a stable and consistent IP address (example: email servers).
• Websites under compliance regulations that demand heightened security measures.

Factors to Consider: Shared vs Dedicated IP Addresses

Several critical factors should be considered when contemplating a dedicated and a shared IP address for your website. Doing so helps ensure your choice aligns with your website’s needs and goals. Below are a few factors to consider when choosing between shared vs dedicated IP addresses:

The impact of IP addresses on SEO is a topic of much debate. Having a shared IP address does not negatively impact a website’s SEO. Search engines have become capable enough to recognize different websites on a shared IP.

If a website on a shared IP is involved in malicious activities and gets blacklisted, this can have a collateral impact on other sites sharing the IP. A dedicated IP eliminates this risk, as the IP reputation is entirely in your control.

The traffic volume your website expects to handle is a significant consideration. For high-traffic sites, a dedicated IP address can be beneficial. It offers more stability and can handle higher traffic loads without the risk of being affected by other sites’ traffic surges, a common issue with shared IPs.

A dedicated IP can provide these resources more reliably if your website requires significant resources. This includes higher bandwidth, more storage, or enhanced processing power.

Security has become a need instead of a choice for websites handling sensitive transactions. This includes e-commerce sites, financial services, or any platform dealing with personal user data. A dedicated IP address offers a higher level of security.

It allows for installing SSL certificates , crucial for encrypting data and secure communication. Having a dedicated IP can help implement more stringent security measures and protocols. This might be necessary to comply with various data protection regulations.

The website hosting and management budget is crucial for many, especially for small businesses or personal websites. Shared IP addresses are more cost-effective, as the server and IP address cost are distributed among all the websites hosted on that server.

This makes it an attractive option for those who are budget-conscious. However, weighing the cost savings against potential drawbacks, such as the ‘neighbor effect’ and limited control, is important.

Also Read: How To Check Server Location? 8 Simple Steps Guide .

Strategies to Protect Your IP Address

Below are a few strategies to protect your IP address:

A Virtual Private Network is one of the best ways to protect your IP address. With a virtual private network (VPN), your internet connection is encrypted and routed via a server located wherever you choose.

This process masks your IP address and replaces it with one from the VPN server. While keeping your IP address hidden from websites and ISPs, a VPN also helps secure your data from eavesdroppers.

Proxy servers function similarly to VPNs . They act as intermediaries between the internet and your device. When you use a proxy server, your internet traffic is routed through the proxy server, hiding your actual IP address.

Proxies can be helpful in bypassing geo-restrictions or for basic IP masking. However, they often lack the strong encryption VPNs offer, making them less secure.

Most modern web browsers offer a private browsing mode (like Incognito in Google Chrome). While private browsing doesn’t hide your IP address from external entities, it can prevent your browser from storing information about your browsing session. This includes cookies, history, or form inputs. This is particularly useful for protecting your privacy from others who might use the same device.

Connecting to public Wi-Fi can effectively mask your home IP address. It does, however, come with considerable security risks. Public Wi-Fi networks are often unsecured, making them hotbeds for cybercriminal activity. If you choose this method, using a VPN to encrypt your connection and shield your data from potential threats is crucial.

The TOR (Onion Router) is a free network for anonymous communication. It routes your internet traffic through several servers, encrypting it at every step. This makes tracing your IP address extremely difficult. Although TOR is a powerful tool for maintaining anonymity, it can slow down your internet connection. It is also unsuitable for data-heavy activities like streaming or downloading large files.

Some Internet Service Providers prioritize user privacy and offer services like dynamic IP allocation. This is where your IP address constantly changes. These ISPs may also provide built-in VPN services. This makes it essential to research reliable ISPs in your area and consider switching to one that offers these privacy-boosting features.

If you’re using a dynamic IP address common with many ISPs, you can change it by restarting your router. This might not be a foolproof method for protecting privacy. However, regularly changing your IP address can make it more challenging for someone to track your online activities over time.

Challenges and Considerations

Although the above strategies offer protection for your IP address, they also come with challenges, including:

• VPN and Tor Network : Tor and VPN sometimes slow internet connections due to the encryption process and traffic routing through several servers.
• Proxy Servers : Not all proxies are secure. Using reputable proxy services is crucial to avoid exposing your data to potentially malicious operators.
• Public Wi-Fi : Public Wi-Fi can still come with risks, even when using a VPN. This makes it essential to be cautious about the activities you perform on these networks.

Also Read: Quick Guide To Modify CentOS 7 Network Config Files .

Below, we shed light on the role of dedicated servers in IP allocation becomes crucial:

A dedicated server is a remote server completely dedicated to an organization, individual, or application. Unlike shared servers, it is not shared with multiple users or organizations. These servers offer robust performance, security, and control over the server environment.

Here are some key characteristics of dedicated servers:

• Exclusive Use : Dedicated servers provide exclusive resources to the user, including CPU, memory, and disk space.
• Performance and Reliability : They offer high performance and reliability since resources are not shared.
• Security and Control : Users have greater control over server configuration, enhancing security and customization.
• Cost : Dedicated servers are more costly than shared hosting solutions, reflecting enhanced capabilities.

Below are a few ways a server plays an integral role in IP allocation:

Unique IP Address Allocation

Each server is typically assigned a unique IP address. This exclusive allocation ensures that the server can be easily identified on the network. It boosts security, and lowers the risk of IP address conflicts common in shared hosting environments.

Enhanced Security and Reputation

Having a unique IP address associated with a server can improve security. It allows for more precise control over inbound and outbound traffic. A unique IP reduces the risk of being blacklisted or negatively impacted by other users’ actions, a common concern in shared IP environments.

Facilitating Secure Connections

Dedicated servers often host websites that require secure connections (HTTPS). A unique IP address is necessary for SSL certificates, which are crucial for encrypting data and ensuring secure transactions.

Supporting Multiple Websites

Organizations using servers can host multiple websites, each with a unique IP address. This setup is beneficial for SEO and helps differentiate traffic and analytics for each site.

Customization and Configuration

Organizations can customize IP address allocation with servers based on their needs. This flexibility includes setting up subnet masks, configuring gateways, and managing DNS settings, which is vital for larger organizations or those with specific network requirements.

Scalability and Growth

As organizations grow, their need for IP addresses increases. Dedicated servers allow for scalable IP allocation strategies, ensuring that businesses can expand their online presence seamlessly without the constraints of limited or shared IP resources.

Efficient IP address allocation is an important aspect of robust network management. Following the best practices in IP address management discussed above can offer several advantages. Some major benefits include operational efficiency, fortifying network security, and preparing the infrastructure for scalable growth.

Regarding efficient IP address allocation, the expertise and solutions offered by RedSwitches are invaluable. We are known for offering premium hosting services and providing many solutions tailored to businesses’ unique needs in managing their network resources.

RedSwitches is a reliable partner in optimizing your IP address allocation strategy. We ensure your network’s integrity and help your business in the evolving digital space. Explore our services now to discover how we can help transform your network management practices.

Q. What is the IP address?

An IP address is a distinctive numerical designation assigned to every device linked to a computer network that communicates using the Internet Protocol. It fulfills two primary purposes. It gives the host’s location within the network and locates the host or network interface.

Q. How to find IP address?

Those wondering how to find my IP location, can follow the directions below:

• On Windows : Access Command Prompt and type ipconfig to find your IP address location under the relevant network adapter.
• On macOS : Go to System Preferences > Network. Choose the network connection, and your IP address will be visible.
• On Linux : Use the ifconfig or ip addr command in the terminal.
• On Mobile Devices : Go to your device’s network settings. Find your IP location listed under the Wi-Fi or mobile data network information.
• Online : You can also lookup an IP address using various online tools and websites specifically designed for IP address lookup.

Q. What is the IP address code?

The term IP address code is not a common term. In the context of the format of an IP address, it’s a numerical label. For IPv4, it is a 32-bit number (e.g., 192.168.1.1). For IPv6, it is a 128-bit number (e.g., 2001:0db8:85a3:0000:0000:7a2e:0380:7534).

Q. How do IP addresses work?

IP addresses work by serving as a distinctive identifier for devices on a network. This allows them to communicate with each other and exchange data.

Q. What is the difference between IPv4 and IPv6 addresses?

IPv4 addresses are 32-bit numerical addresses. IPv6 addresses are 128-bit hexadecimal addresses. They offer a larger address space for devices and improved security features.

Q. Why is IP address security important?

IP address security is crucial for protecting personal privacy. It prevents unauthorized access and protects against cyber threats and malicious activities.

Q. How can I hide my IP address?

You can hide your IP address using a proxy server or VPN (virtual private network). Doing so enables you to browse the internet anonymously.

Q. What is a MAC address?

A MAC address, or Media Access Control address, is a unique number linked to network interfaces so that they can communicate with one another inside a network segment.

Q. How can I find the physical location of an IP address?

You can find the physical location of an IP address using IP location tools or services available online that provide geolocation data.

Q. Why use a static IP address?

Using a static IP address ensures that the assigned address remains constant. This is beneficial for certain network configurations and applications requiring a fixed IP.

Q. What is the best way to check my IP address in Windows?

The best way to check your IP address in Windows is to use the command prompt and enter “ipconfig” to view the assigned IP address and related network information.

Check Out Pre-Configured Bare-Metal Servers

Custom Solutions

• Instant dedicated server
• Dedicated Server
• Managed Dedicated Server
• Bare Metal Server
• Dedicated Server with Bitcoin
• 10Gbps Dedicated Server
• Crypto Hosting
• Storage Dedicated Server
• High Availability Cluster
• Video & IPTV Streaming
• CDN & VPN Hosting
• Ad-Tech & Mar-Tech Hosting
• Server Locations

Support Tools

• Affiliate Program
• Client Area
• Support Ticket
• Service Agreement
• Terms Of Service
• Acceptable Use Policy
• Privacy Policy

RedSwitches Is a global hosting provider offering Dedicated Servers, Infrastructure As a Service, Managed Solutions & Smart Servers in 20 global locations with the latest hardware and premium networks.

20 Collyer Quay, #09-01, Singapore 049319

[email protected]

• WHY REDSWITCHES?

Follow us on

2024 RedSwitches Pte. Ltd. All Rights Reserved.

Made With ♥ In Singapore

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Assigning IP Address ranges - Protocol, Best Practices [closed]

I am looking for standard procedures when assigning a range for static ip addresses. Which are the most commonly used approaches and why. I am trying to look on the internet and this forum, however all the answers I find to this question are vague.

Let's say I have a x.x.x.1 /24 (1-254) , multiple switches 2-4, multiple servers 8-16 and multiple idracs 8-16.

Should I start from the bottom and use the first ip-addresses for the switches? which is the best logic?

• Unfortunately, questions about "best practices" lead to multiple opinions which are off-topic here. –  Ron Trunk Commented Aug 13, 2018 at 11:39

There is no one-size-fits-all approach to this, as needs vary widely. Networks are often heavy on switches and routers, servers, or laptops, but very rarely all of these.

For a typical self-contained /24, I'd suggest something like the following, based on a layout I made for a client with many small offices and which they used for about 20 years now.

• .1 to .7 routers
• .8 to .15 switches (from bottom) / access points (from top)
• .16 to .31 specials
• .32 to .47 servers (application from bottom, DNS etc from top)
• .48 to .63 printers
• .64 to .239 DHCP laptops/workstations
• .240 to .254 static laptops/workstations

Servers are allocated in pairs, so there's space for a backup machine if required. Ie file servers might be 32, 34 ..., name servers might be 46, 44 ... Specials are for things which you have few of, perhaps scanners, CCTV, audio; perhaps in your case you'd assign those addresses for your iDRACs.

For more unusual networks, you need to design your own.

Not the answer you're looking for? Browse other questions tagged switch ip-address networking or ask your own question .

• Featured on Meta
• We've made changes to our Terms of Service & Privacy Policy - July 2024
• Announcing a change to the data-dump process

Hot Network Questions

• Some mathematician with mental illness who was a friend of Paul Erdős that has some open problems in Combinatorics
• In what way are we one in Christ Jesus?
• How to become Emperor of the Galaxy
• parallelStream with collect method()
• Is expired sushi rice still good
• Inserting a 0 in Specific Strings
• Why would radio-capable transhumans still vocalise to each-other?
• Why do tip vortices seem to 'bend' inwards at the tip of a plane wing?
• When I use SSH tunneling, can I assume that the server does not need to be trusted?
• What does ボール運び mean, exactly? Is it only used in basketball?
• What are the specific terms for breaking up English words into roots/components
• Political Relations on an Interstellar Scale
• Movie identification 90s-ish on the Syfy channel sea creature
• Does the notion of "moral progress" presuppose the existence of an objective moral standard?
• One Page IDP issued by Govt. Of India not acceptable in Japan
• Split column into lines using awk
• Why do repeating 8's show up more often in these decimals of square roots?
• Possibly manipulated recommendation letter - inform alleged author?
• IQ test puzzle with diagonal line of clocks
• How can a vulnerable function can be a exploited by a non-logged user if it only called in the WP admin section of a plugin?
• What is the “history“ of mindfulness
• How to contain a transcontinental empire?
• How to reconcile different teachings of Jesus regarding self defense?
• Why don't neutrons and protons have variable spin?

Best practices for fixed IP addresses for certain assets (manged switch, IP cam,

This question probably falls into the bucket of “afraid to ask”…

What is the best practice recommendation for using fixed IP addresses for special assets such as manged switches or IP cam’s?

Using DHCP reservation or fixed IP outside of DHCP range? What are the implications.

I use static IPs for everything . Why not? How often do you assign an IP to a camera that you need to worry about it? Once. PCs, switches, servers, etc. Once.

Because I assign the IP, I know what’s at that address. I don’t need to manage the DHCP server to manage my IPs.

I honestly don’t get the love affair with DHCP and “reservations.”

Even my VPN clients have a static IP set on their virtual NICs. No DHCP at all.

Static as well. The only thing I use DHCP reservations for is if for some reason a workstation needs a fixed IP address and even then that’s not often.

The only time this becomes an issue is you need to re-number your network. I’ve had to do this exactly twice in 30 years. One was a company that just picked random 192.168 subnets for each location but didn’t account for growth where they might need more than one subnet per location. I moved them to a 10.location.network.xx schema.

The second was a small company that was 192.168.0.xx and kept running into problems when home users and consultants needed to VPN in and many of them had 192.168.0 for their home networks.

Just have a xls or Googlesheet to list the IP addresses. Many people do not use DHCP for appliances as why put certain appliances under points of failure or reliance like DHCP servers ?

Different administrators may have different definitions for static IP address. In my understanding, a reserved DHCP address is still a dynamic IP address as it is dynamically assigned by DHCP server with a defined preference policy. It does not guarantee to get such reservations assigned. E.g. when you configure a reservation in DHCP, such IP address might still be in use, e.g. by some undocumented manual assignment of static IP address or by a previous dynamic IP address assignment and the lease time not yet over nor needing renewal currently. That’s also a reason why you want to lower lease times significantly in preparation of a reordering of dynamic IP addresses.

Many DHCP server implementations allow to configure reservations within scope of dynamic IP addresses as well as outside of that scope. Defining reservations inside scope of dynamic IP addresses leads to more confusion.

I don’t know which variant is best or better practice. But I know what is worse practice. I consider a practice worse when it uses reservations inside the scope of dynamic IP addresses. I also consider a practice worse when it uses static IP address assignment without documenting nor managing such statically assigned IP addresses.

But not every device supports static IP address assignment. This applies to IP cameras to where not every model supports static IP address assignment.

When you need to assign several IP addresses to same NIC, this is usually not supported by DHCP while usually no issue for manual configuration of static IP address assignment. Then there are devices with several NICs, e.g. notebooks and servers. Often, servers use static IP addresses and notebooks dynamic IP addresses. So if you keep several NICs active for devices with dynamic IP addresses, your IP address assignment policy needs to cope with such cases and not consider it as unexpected. And you usually don’t want to create loops.

The most important thing is that you manage your ip address space. Whether that is to just use fixed, like Robert, or DHCP with reservations, or whatever. It is important to know how many addresses you are using, how many you have free, and what the addresses of key elements are. The method you use to do this is secondary.

Good point. When I changed us from 192.168.x.x./24 networks to our current /17 networks and inter-campus VPNs, I programmed the classic “router on a stick.” We then migrated devices a block at a time while maintaining access to everything as we moved. Finally, we just removed the old gateway from the router and we were done. It was practically painless.

I did something very similar. They were doing l3 routing on their hp switches and we just added the extra subnets. The only place that required extra care was switching over the firewall and directly connected switch subnet at remote sites.

I think you’ll get a variety of answers on this one…

I assign static (rarely) where I think it’s required, and I make a DHCP reservation as well. The reservation doesn’t even have to the correct mac address, it just prevents a device set to dynamic from hitting the same IP.

For anything I’ve managed or deemed important I would set a static IP to it. That way I know exactly where it’s at and if the device is online or not. If a device is in the DHCP range then it’s likely an employee assigned device, like a desktop or laptop.

Static: Router, Hypervisors, iDRAC/iLO, Domain Controller (if Windows network) or LDAP/other auth server (for other environments.

DHCP Reservation: Printers, NAS, Fileservers, database servers

No fixed address: Switches, computers, other crap on the network.

If this is a problem that makes you think you should not use DHCP reservations, your network has other issues to fix.

Obviously, as it is till DHCP.

Mine is. Obviously…

100% the #1 thing. Planning is always key.

I set static for anything you will need to manage. Servers, switches, routers, printers, etc Basically anything you will need to RDP or SSH into or configure through web GUI. You can use hostname a lot of that but I always like to have the IP as well. Leave the first 50-100 (whatever you need, plan for growth) IP addresses in your subnet out of the DHCP lease pool. Use those for static IPs.

The only time I use reservations is when an end user device needs a dedicated IP for whatever reason. I prefer this over static IPs as it’s easy to claim that IP back from the DHCP server rather than having to get on the end user device. Plus if your end users take their device to other networks they would have to change those settings anyway.

All end user devices and usually wireless access points get DHCP IPs. You don’t have to worry about conflicts with other networks when those devices leave. You almost never need to connect directly to a wireless AP so leaving those for DHCP has no real downside.

Best Practice? Don’t set a fixed IP address that’s not permitted to have internet access by your firewall, unless intentional. Better yet, don’t give the device a DNS address, if it doesn’t need it.

Well, I am a solid mixed. Only if there’s no other way do I set a reservation in a DHCP scope. Workstations / laptops go in the DHCP scope, everything else goes in a static IP range - Servers, UPS, switches and printers. Oddball stuff like mail machines and security systems are set to static as well usually within a range as well.

I’m a huge fan of the same thing only different subnet. X.Y.Z.15? Oh, that’s the DC for that office. I do like setting multihomed machines with sequential numbers, but it doesn’t always work.

In small networks, I try to assign 1-25 server for stuff (DCs, app servers, and their UPS’s ). Switches too if you can afford to shoehorn them. At 25-50 I like put switchgear and or printers if I can. 50-75 would be the next block to put printers or switches if I have a lot of one or the other. Then, I set an appropriate scope for the transients, usually starting at 100. If almost nothing is transient, then don’t make a big scope. If most everyone is a nomad, then I usually set my DHCP scope to 10% over maximum nodes, because well, consultants.

If I have headroom in the IP space, I like to put the oddball stuff (Static) like plotters and the drink machines in the lounge high in the IP space.

This scheme works for both large and small organizations. Larger site often have different subnets for the individual floors, or implement VLANs as appropriate.

Also as a matter of experience try to keep the lowest few and the highest few open as long as possible, because some ISP or another will want them… LOL

Horses for courses. Size of environment is a factor. DHCP wherever possible, static for network/security device only. image 4000 printers over 300 offices - you wouldn’t want to manually assign those. why would you care what Ip a camera has etc…

In large organizations with many more than 10.000 devices attached to network, there often exist IPAM tools for provisioning also statically assigned IP addresses. They don’t need to be assigned manually. SME usually don’t have such IPAM tools and hence will often be limited to manual assignment. I did not manage such IPAM tools and hence have no experience which management options these provide.

In order to prevent a device with a static IP from taking an address in the DHCP scope, you should really just adjust the DHCP scope to not include that IP address in the pool. What you’re doing technically works, but it’s the wrong use case for what the reservations are for.

If the addresses are in the “middle” of the scope, such that the scope cannot be reduced from the start or end of the range, then you can create exclusion ranges for that. Not any more work than creating a reservation, and it doesn’t require you to use made-up MAC addresses, etc.

If it’s something that you may need to access for management later, and you need to be able to do it via a known IP address rather than by name, then you should give it a static IP address. Otherwise, DHCP is a good course of action. DHCP is also useful for devices which may need to be used on different networks at different times (such as laptops).

Consider that if your environment has laptops which you give static IPs to, that if the users take those home, their laptops will not work (unless their home networks happen to use the same subnet as your work office).

If your file server and printers are reliant upon DHCP for addresses, and your DHCP server goes down, then you will have servers and other core infrastructure items which are unavailable until the DHCP server is back up. You could argue that “well the laptops would be down too then” but with statically-assigned server IP’s, theoretically, you could get the C-level folks running with some quickly assigned static IPs for temporary use to appease them while you get the real issue fixed. That sort of thing. It gives you options if the servers themselves are running on static already.

Related Topics

• Skip to content
• Skip to search
• Skip to footer

Configuration Management: Best Practices White Paper

Available languages, download options.

• PDF (20.2 KB) View with Adobe Reader on a variety of devices

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

Introduction

Configuration management is a collection of processes and tools that promote network consistency, track network change, and provide up to date network documentation and visibility. By building and maintaining configuration management best-practices, you can expect several benefits such as improved network availability and lower costs. These include:

Lower support costs due to a decrease in reactive support issues.

Lower network costs due to device, circuit, and user tracking tools and processes that identify unused network components.

Improved network availability due to a decrease in reactive support costs and improved time to resolve problems.

We have seen the following issues resulting from a lack of configuration management:

Inability to determine user impact from network changes

Increased reactive support issues and lower availability

Increased time to resolve problems

Higher network costs due to unused network components

This best-practice document provides a process flowchart for implementing a successful configuration management plan. We'll look at the following steps in detail: create standards , maintain documentation , and validate and audit standards .

High-Level Process Flow for Configuration Management

The diagram below shows how you can use the critical success factors followed by performance indicators to implement a successful configuration management plan.

Create Standards

Creating standards for network consistency helps reduce network complexity, the amount of unplanned downtime, and exposure to network impacting events. We recommend the following standards for optimal network consistency:

Software version control and management

IP addressing standards and management

Naming conventions and Domain Name System/Dynamic Host Configuration Protocol (DNS/DHCP) assignments

Standard configurations and descriptors

Configuration upgrade procedures

Solution templates

Software Version Control and Management

Software version control is the practice of deploying consistent software versions on similar network devices. This improves the chance for validation and testing on the chosen software versions and greatly limits the amount of software defects and interoperability issues found in the network. Limited software versions also reduce the risk of unexpected behavior with user interfaces, command or management output, upgrade behavior and feature behavior. This makes the environment less complex and easier to support. Overall, software version control improves network availability and helps lower reactive support costs.

Note:  Similar network devices are defined as standard network devices with a common chassis providing a common service.

Implement the following steps for software version control:

Determine device classifications based on chassis, stability, and new feature requirements.

Target individual software versions for similar devices.

Test, validate, and pilot chosen software versions.

Document successful versions as standard for similar-device classification.

Consistently deploy or upgrade all similar devices to standard software version.

IP Addressing Standards and Management

IP address management is the process of allocating, recycling and documenting IP addresses and subnets in a network. IP addressing standards define subnet size, subnet assignment, network device assignments and dynamic address assignments within a subnet range. Recommended IP address management standards reduce the opportunity for overlapping or duplicate subnets, non-summarization in the network, duplicate IP address device assignments, wasted IP address space, and unnecessary complexity.

For example, let's take a large enterprise network with an east coast campus, a west coast campus, a domestic WAN, a European WAN, and other major international sites. The organization allocates contiguous IP classless interdomain routing (CIDR) blocks to each of these areas to promote IP summarization. The organization then defines the subnet sizes within those blocks and allocates sub-sections of each block to a particular IP subnet size. Each major block or the entire IP address space can be documented in a spreadsheet showing allocated, used, and available subnets for each available subnet size within the block.

The next step is to create standards for IP address assignments within each subnet range. Routers and Hot Standby Router Protocol (HSRP) virtual addresses within a subnet might be assigned the first available addresses within the range. Switches and gateways may be assigned the next available addresses, followed by other fixed address assignments, and finally dynamic addresses for DHCP. For example, all user subnets may be /24 subnets with 253 available address assignments. The routers may be assigned the .1 and .2 addresses, and the HSRP address assigned the .3 address, switches .5 through .9, and the DHCP range from .10 through .253. Whatever standards you develop, they should be documented and referenced on all network engineering plan documents to help ensure consistent deployment.

Naming Conventions and DNS/DHCP Assignments

Consistent, structured use of naming conventions and DNS for devices helps you manage the network in the following ways:

Creates a consistent access point to routers for all network management information related to a device.

Reduces the opportunity for duplicate IP addresses.

Creates simple identification of a device showing location, device type, and purpose.

Improves inventory management by providing a simpler method to identify network devices.

Most network devices have one to two interfaces for managing the device. These may be an in-band or out-of-band Ethernet interface and a console interface. You should build naming conventions for these interfaces related to the device type, location, and interface type. On routers, we strongly recommend using the loopback interface as the primary management interface because it can be accessed from different interfaces. You should also configure loopback interfaces as the source IP address for traps, SNMP and syslog messages. Individual interfaces can then have a naming convention that identifies the device, location, purpose, and interface.

We also recommend identifying DHCP ranges and adding them to the DNS, including the location of the users. This may be a portion of the IP address or a physical location. An example might be "dhcp-bldg-c21-10" to "dhcp-bldg-c21-253", which identifies IP addresses in building C, second floor, wiring closet 1. You can also use the precise subnet for identification. Once a naming convention has been created for devices and DHCP, you'll need tools to track and manage entries, such as Cisco Network Registrar .

Standard Configuration and Descriptors

Standard configuration applies to protocol and media configurations, as well as global configuration commands. Descriptors are interface commands used to describe an interface.

We recommend creating standard configurations for each device classification, such as router, LAN switch, WAN switch, or ATM switch. Each standard configuration should contain the global, media, and protocol configuration commands necessary to maintain network consistency. Media configuration includes ATM, Frame Relay, or Fast Ethernet configuration. Protocol configuration includes standard IP routing protocol configuration parameters, common Quality of Service (QoS) configurations, common access lists, and other required protocol configurations. Global configuration commands apply to all like devices and include parameters such as service commands, IP commands, TACACS commands, vty configuration, banners, SNMP configuration, and Network Time Protocol (NTP) configuration.

Descriptors are developed by creating a standard format that applies to each interface. The descriptor includes the purpose and location of the interface, other devices or locations connected to the interface, and circuit identifiers. Descriptors help your support organization better understand the scope of problems related to an interface and allows faster resolution of problems.

We recommend keeping standard configuration parameters in a standard configuration file and downloading the file to each new device prior to protocol and interface configuration. In addition, you should document the standard configuration file, including an explanation of each global configuration parameter and why it is important. Cisco Resource Manager Essentials (RME) can be used to manage standard configuration files, protocol configuration, and descriptors.

Configuration Upgrade Procedures

Upgrade procedures help ensure that software and hardware upgrades occur smoothly with minimal downtime. Upgrade procedures include vendor verification, vendor installation references such as release notes, upgrade methodologies or steps, configuration guidelines, and testing requirements.

Upgrade procedures may vary widely depending on network types, device types, or new software requirements. Individual router or switch upgrade requirements may be developed and tested within an architecture group and referenced in any change documentation. Other upgrades, involving entire networks, can not be tested as easily. These upgrades may require more in-depth planning, vendor involvement, and additional steps to ensure success.

You should create or update upgrade procedures in conjunction with any new software deployment or identified standard release. The procedures should define all steps for the upgrade, reference vendor documentation related to updating the device, and provide testing procedures for validating the device after the upgrade. Once upgrade procedures are defined and validated, the upgrade procedure should be referenced in all change documentation appropriate to the particular upgrade.

Solution Templates

You can use solution templates to define standard modular network solutions. A network module may be a wiring closet, a WAN field office, or an access concentrator. In each case you need to define, test and document the solution to help ensure that similar deployments can be carried out in exactly the same way. This ensures that future changes occur at a much lower risk level to the organization since behavior of the solution is well defined.

Create solution templates for all higher-risk deployments and solutions that will be deployed more than once. The solution template contains all standard hardware, software, configuration, cabling, and installation requirements for the network solution. Specific details of the solution template are shown as follows:

Hardware and hardware modules including memory, flash, power, and card layouts.

Logical topology including port assignments, connectivity, speed, and media type.

Software versions including module or firmware versions.

All non-standard, non device-specific configuration including routing protocols, media configurations, VLAN configuration, access lists, security, switching paths, spanning tree parameters, and others.

Out-of-band management requirements.

Cable requirements.

Installation requirements including environmentals, power, and rack locations.

Note that the solution template does not contain many requirements. Specific requirements such as IP addressing for the specific solution, naming, DNS assignments, DHCP assignments, PVC assignments, interface descriptors, and others should be covered by overall configuration management practices. More general requirements, such as standard configurations, change management plans, documentation update procedures, or network management update procedures, should be covered by general configuration management practices.

Maintain Documentation

We recommend documenting the network and changes that have occurred in the network in near real-time. You can use this precise network information for troubleshooting, network management tool device lists, inventory, validation, and audits. We recommend using the following network documentation critical success factors:

Current device, link, and end-user inventory

Configuration version control system

TACACS configuration log

Network topology documentation

Current Device, Link, and End-User Inventory

Configuration version control system.

A configuration version control system maintains the current running configurations of all devices and a set number of previous running versions. This information can be used for troubleshooting and configuration or change audits. When troubleshooting, you can compare the current running configuration to previous working versions to help understand if configuration is linked to the problem in any way. We recommend maintaining three to five previous working versions of the configuration.

TACACS Configuration Log

To identify who made configuration changes and when, you can use TACACS logging and NTP. When these services are enabled on Cisco network devices, the userid and timestamp is added to the configuration file at the time the configuration change is made. This stamp is then copied with the configuration file to the configuration version control system. TACACS can then act as a deterrent for unmanaged change and provide a mechanism to properly audit changes that occur. TACACS is enabled using the Cisco Secure product. When the user logs into the device, he/she must authenticate with the TACACS server by supplying a userid and password. NTP is easily enabled on a network device by pointing the device to an NTP master clock.

Network Topology Documentation

Topology documentation aids in the understanding and support of the network. You can use it to validate design guidelines and to better understand the network for future design, change, or troubleshooting. Topology documentation should include both logical and physical documentation, including connectivity, addressing, media types, devices, rack layouts, card assignments, cable routing, cable identification, termination points, power information, and circuit identification information.

Maintaining topology documentation is the key to successful configuration management. To create an environment where topology documentation maintenance can occur, the importance of the documentation must be stressed and the information must be available for updates. We strongly recommend updating topology documentation whenever network change occurs.

Validate and Audit Standards

Configuration management performance indicators provide a mechanism to validate and audit network configuration standards and critical success factors. By implementing a process improvement program for configuration management, you can use the performance indicators to identify consistency issues and improve overall configuration management.

We recommend creating a cross-functional team to measure configuration management success and improve configuration management processes. The first objective of the team is to implement configuration management performance indicators in order to identify configuration management issues. We'll discuss the following configuration management performance indicators in detail:

Configuration integrity checks

Device, protocol, and media audits

Standards and documentation review

After evaluating the results from these audits, initiate a project to fix inconsistencies and then determine the initial cause of the problem. Potential causes include a lack of standards documentation or a lack of a consistent process. You can improve standards documentation, implement training, or improve processes to prevent further configuration inconsistency.

We recommend monthly audits, or possibly quarterly if only validation is needed. Review past audits to confirm that past problems are resolved. Look for overall improvements and goals to demonstrate progress and value. Create metrics to show the quantity of high-risk, medium-risk, and low-risk network configuration inconsistencies.

Configuration Integrity Checks

The configuration integrity check should evaluate the overall configuration of the network, its complexity and consistency, and potential issues. For Cisco networks, we recommend using the Netsys configuration validation tool. This tool inputs all device configurations and creates a configuration report that identifies current problems such as duplicate IP addresses, protocol mismatches, and inconsistency. The tool reports any connectivity or protocol issues, but does not input standard configurations for evaluation on each device. You can manually review configuration standards or create a script that reports standard configuration differences.

Device, Protocol, and Media Audits

Device, protocol, and media audits are a performance indicator for consistency in software versions, hardware devices and modules, protocol and media, and naming conventions. The audits should first identify any non-standard issues, which should lead to configuration updates to fix or improve the issues. Evaluate overall processes to determine how they could prevent suboptimal or non-standard deployments from occurring.

Cisco RME is a configuration management tool that can audit and report on hardware versions, modules and software versions. Cisco is also developing more comprehensive media and protocol audits that will report inconsistency with IP, DLSW, Frame Relay and ATM. If a protocol or media audit is not developed, you can use manual audits, such as reviewing devices, versions and configurations for all like devices in a network, or by spot checking devices, versions and configurations.

Standards and Documentation Review

This performance indicator reviews network and standards documentation to ensure that the information is accurate and up to date. The audit should include reviewing current documentation, recommending changes or additions, and approving new standards.

You should review the following documentation on a quarterly basis: standard configuration definitions, solution templates including recommended hardware configurations, current standard software versions, upgrade procedures for all devices and software versions, topology documentation, current templates, and IP address management.

Related Information

• Technical Support - Cisco Systems

Was this Document Helpful?

Contact Cisco

• (Requires a Cisco Service Contract )

TechRepublic

TechRepublic | Forums | Networks

• Register Now or SIGN IN to post
• Recent Activity
• Creator Topic

Assigning IP Address ranges – is there a “Best Practices” document?

by wfairley · about 16 years, 4 months ago

I feel like I am trying to herd cats at work – I would really like to standardize how we assign IP addresses within DHCP and the subnets, but each administrator has his or her own “Best Practices” ideas about IP Address schemes – one person uses x.x.x.1 as the gateway/router, while another uses x.x.x.254, and yet another will use x.x.x.2. One administrator will use x.x.x.30 through x.x.x.100 as the DHCP range, while another will use x.x.x.100 through x.x.x.200 and so on. One administrator even used a range in the middle of his DHCP scope for switches, routers, and servers!

I want to do something like this: x.x.x.1 = default gateway (assuming /24) 2-20 = network access devices 21-40 = server devices 41-60 = network peripherals (printers, etc.) 61-80 = reserved for special devices 81-100 = static addressed workstations 101-200 = standard DHCP pool of addresses 201-254 = VOIP devices (switch, adapters, etc.)

BUT ~ I can’t convince everyone to do it the same way. They want to see a “Best Practices” document from an authoritative source, and I don’t blame them, I do too. This has led into some heated but healthy discussions about ITIL and IT Service Management, areas in which I am still learning more.

Any feedback? Does such a document exist?

Thanks in advance!

All Answers

• Author Replies

Clarifications

In reply to Assigning IP Address ranges – is there a “Best Practices” document?

I’ve never seen one…

by fregeus · about 16 years, 4 months ago

…and i doubt there is one. DHCP range assignment is very situation specific. Some networks don’t have VioP devices, some don’t have servers, some don’t have printer or workstations.

I think your best bet is to get everyone involved in a conference room and hammer out your own standard.

TCB edited for typos

No real best practice… subnetting is how it’s really done.

by cg it · about 16 years, 4 months ago

I don’t think designing a network by IP address is considered SOP, though, it’s a factor in design.

Also, assigning addresses isn’t just a matter of wanting to be able to identify what host is what address.

There are many factors to use in the design process which effects what addresses to use. # of hosts needed. Security required, delegation of administration, any growth plans.

Besides, you will have to use MAC filtering in DHCP to ensure that hosts get the correct pool addresses. Not a monumental task but does tend to create more administrative effort when you retire older equipment, replace broken equipment, upgrade equipment, replace faulty NICs, blah blah blah.

A few options

by michael kassner · about 16 years, 4 months ago

There are two schools of thought when it comes to this subject. There are those who like to compartmentalize the IP addrs and obviously those that do not.

The first approach is a great idea, but then you run into devices that do not fit into compartments and what do you do with them? There are other problems as well, what if you run out of IP addrs for a specific group?

I subscribe to the second approach for most of my clients and then immediately mention that they need to get a good inventory documentation application that will automatically provide all of the pertinent information about any given device.

Cisco has a great article about all of this and might be helpful to you.

http://www.cisco.com/en/US/tech/tk869/tk769/technologies_white_paper09186a008014f924.shtml#topic4

This is the closest I’ve seen what I’m looking for…

In reply to A few options

Thanks Michael! This Cisco document actually presents some “core” address assignments within subnets, such as suggested address assignments for gateways, special devices, and standard DHCP ranges, as well as naming conventions, etc. It is very helpful!

To put my request in context, I currently work for a small telecom company that occasionally gets a network consultant type sell for small firms in my city, predominantly law firms and doctor offices, with fewer than 20 people, so VLANs and subnetting are rarely necessary. By defining some standard practices regarding address ranges and assignments, we can improve our response times for outages, improve our documentation efficiency, even improve our install lead times and install process times.

This document takes me in the right direction, but I will continue my search, then publish my own “Best Practices” document in the TechRepublic forums and look for feedback.

Thanks again Michael!

In reply to This is the closest I’ve seen what I’m looking for…

Well, Cisco did all of the work. I would very much appreciate hearing about the final plan that you come up with. For the most part it is very specific to the situation being discussed, but I have never been led astray by Cisco.

Your better off approaching this

by dumphrey · about 16 years, 4 months ago

from a standards and procedures vector. Since this is mostly a pet peeve of yours, its your responsibility to show what financial, management, and security benefits are to be had by developing an internal standard.

Create a TechRepublic Account

Get the web's best business technology news, tutorials, reviews, trends, and analysis—in your inbox. Let's start with the basics.

* - indicates required fields

Sign in to TechRepublic

Lost your password? Request a new password

Reset Password

Please enter your email adress. You will receive an email message with instructions on how to reset your password.

Check your email for a password reset link. If you didn't receive an email don't forgot to check your spam folder, otherwise contact support .

Welcome. Tell us a little bit about you.

This will help us provide you with customized content.

Want to receive more TechRepublic news?

You're all set.

Thanks for signing up! Keep an eye out for a confirmation email from our team. To ensure any newsletters you subscribed to hit your inbox, make sure to add [email protected] to your contacts list.

• Remember me Not recommended on shared computers

Forgot your password?

Or sign in with one of these services

• Best Practices

IP Address Assignment

By Waring192 September 28, 2020 in Best Practices

• Reply to this topic
• Start new topic

Recommended Posts

Just wondering how everyone assigns there IP's, vlans, subnets etc? It would be interesting to see how dealers address the situation so it doesn't become a random way.

Link to comment

Share on other sites, mstafford388.

Flat network unless we have devices known to cause issues that need to be on their own VLAN.  Depending on the scope of the project DHCP is fine for many devices these days, we typically use DHCP reservations for systems that warrant assigned IP addresses.  Certain devices always get assigned IPs.  

I am guessing that he means do people have strategies for numbering within your LAN.

I use 1-10 for networking hardware like router, WAPs, switches. (ie 192.168.1.1 - 192.168.1.10)

My C4 controllers are from 11-19.

My PCs are from 85-99.

My DHCP range is from 100-200.

I use 30-39 for cameras.

I am thinking of going to a /23 subnet but that may f(&% up stuff for a bit as I will undoubtedly forget to change some things that have static settings.  I am starting to run out of room on your typical /24 subnet as I have a bunch of dockers running on unRAID and I like to use unique IPs for them so that I don't have to screw around and change HTTP from port 80 to all sorts of funky ports.

It depends on how sophisticated your network is and how much expertise you have in-house. I usually have two VLANS to keep IoT devices secure and write some firewall policies to allow the traffic back and forth so users can't tell the difference. But a lot of the gateways/routers that AV integrators use wouldn't be able to do this. Pakedge, for example, doesn't allow for this sort of traffic between VLANs. 

Control4Savant

I just DHCP'em and then reserve the lease for whatever address they get first time they connect.  Keep a spreadsheet / export from the router config that shows all of them.

Static assignments from inside the router or switch for all manages devices. VLANs for traffic separation and privacy isolation for IoT devices and guest network. IP cameras should always be on NVR internal or isolated network for security. Customer unique VPN address. Larger subnets bigger commercial spaces or larger lighting systems.  

• Köhler Medientechnik and womble123

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.    Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.    Display as a link instead

×   Your previous content has been restored.    Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

• Insert image from URL
• Submit Reply
• Existing user? Sign In
• Online Users
• All Activity
• My Activity Streams
• Unread Content
• Content I Started
• Subscriptions
• Leaderboard
• Create New...

Important Information

By using this site, you agree to our Terms of Use .