IPv6 Address Plans

Note: There is no shortage of material on the subject of Internet Protocol version 6 (IPv6) address plans. A google search for "IPv6 address plan" or "IPv6 address planning" returns about ten thousand results. The articles, presentations, and books referenced in topics 1 and 2 below provide an introduction to IPv6 address planning. Topics 3 - 7 below discuss specific aspects of IPv6 address planning.

This IPv6 Address Plans article contains 7 topics:

1. Basic Information
2. More Detailed Information
3. Voices of Experience
4. Internet Protocol Address Management (IPAM) software and Address Planning
5. Examples of Actual IPv6 Address Plans
    5.1 Examples from Organizations in the United States (US)
    5.2 Examples from Organizations Outside the US
6. IPv6 Subnet Planning
7. Tools That May Help 

1. Basic Information

As Internet Engineering Task Force (IETF) Request for Comments (RFC) 9099 observes;

A key task for a successful IPv6 deployment is to prepare an addressing plan. Because an abundance of address space is available, structuring an address plan around both services and geographic locations allows address space to become a basis for more structured security policies to permit or deny services between geographic regions.

This article and this more in-depth article introduce the organizational and technical challenges involved in IPv6 address planning, including a basic discussion of IPv6 subnet planning. For books on IPv6 address planning see part 3 of the IPv6 Training and Learning Information document in the IPv6 Training and Learning article in the Deployment section.

A word of caution: IPv6 address planning is not something that happens only once, and then you are done with it. After a network has transitioned from using IPv4-only to using dual-stack (both IPv6 and IPv4) or IPv6-only addressing, there will inevitably come a time when it will be necessary to transition the network from using that set of addresses to using yet another set of IPv6-only addresses. When that time comes, this article on The Headache of IPv6 Readdressing will become pertinent. This article emphasizes the need for careful consideration before enabling unique local addressing (ULA).

2. More Detailed Information

This article provides an informative discussion of the dramatic differences involved in IPv6 address planning compared to IPv4 address planning and expands on the cautions provided by an earlier article against the continued use of outdated IPv4 address planning practices. This series of articles in 3 parts (part1, part2, and part3) from ERNW Insinuator provides practical guidelines and considerations involved in IPv6 address planning. Marc Uebel of GestióIP provides an example of a hierarchical address plan.

This document and this presentation from Cisco Systems, Inc. provides additional guidelines and cautions about IPv6 address planning, while this presentation (based on earlier Cisco presentations) discusses the planning process from several viewpoints. This document from the Samenwerkende Universitaire Reken Faciliteiten network (SURFnet) group, this article from the Internet Society (ISOC), and this article from the Réseaux IP Européens (RIPE) Network Coordination Centre (NCC) (together with the Further Reading list of articles at the end) provide additional guidelines and examples to aid in IPv6 address planning and the IPv6 Framework for European Governments provides address planning guidelines in chapter 8 of Guidelines and Process: IPv6 for Public Administrations in Europe. This document from Oxford University describes their approach to allocation and management of IPv6 addresses at the university.

This American Registry for Internet Numbers (ARIN) IPv6 wiki IPv6 Addressing Plans article provides a collection of informal suggestions and guidelines for IPv6 address planning while the TeamARIN article, APNIC article, and Infoblox article provide suggestions and guidelines for service providers. This article from the African Network Information Center (AfriNIC) offers guidelines about what NOT to do during IPv6 address planning for homes and Small Offices/Home Offices (SOHO). RFCs 6177, 6883 and 7381 section 2.6, and this draft document updating RFC 6177 provide in-depth technical recommendations.

The Infoblox Inc. 6MAP wizard presentation and IPv6 Resources section of their IPv6 Center of Excellence web page provide links to additional IPv6 address planning tools and articles. Some of the tools are specific to Infoblox Inc products, but others can be useful in any IPv6 address planning effort. This Infoblox presentation (video available here) discuss an IPv6 Address Plan Case-Study.

3. Voices of Experience

A best practices document describes actions or practices that are known to produce good outcomes when followed. Presentations offering suggestions and best practices for IPv6 address planning based on their experience are provided by Ron Broersma, Defense Research and Engineering Network (DREN), Owen DeLong, Hurricane Electric, and Jeff Doyle, Jeff Doyle and Associates Inc. This ERNW Insinuator article (video available here) offers lessons learned during 5 years of hands-on address management on IPv6 networks.

4. IPAM software and Address Planning

This Frequently Asked Questions (FAQ) article answers questions about IPAM software. This paper discusses best practices when using IPAM software. This paper describes ways IPAM software can assist in IPv6 address planning. Several commercial and open-source IPAM programs for automating various aspects of planning, tracking and managing IPv6 addresses are available. One list of IPAM programs is available here. Another list of IPAM programs is available here (at the bottom of the page). Since 2012, Microsoft’s Windows server software includes an IPAM feature (see Part 3: IPv6 Static Addressing and DNSv6 in the Enabling IPv6 in Microsoft Windows Application Servers article in the Infrastructure section for more information). The NetDot and HaCi tools provide automated ways to collect, organize, and maintain IPv6 network addressing information once the resulting network is in operation.

5. Examples of Actual IPv6 Address Plans

5.1 Examples from Organizations in the US

One publicly available IPv6 address plan is this draft Veterans Affairs IPv6 Address Plan. Some lessons learned during the development of the Department of Veterans Affairs IPv6 address plan are available here. The IPv6 address plan used by the University of Pennsylvania is available here. The IPv6 address plan used by the University of Wisconsin-Madison is available here. The International Civil Aviation Organization IPv6 address plan is available here. The Department of Defense (DoD) IPv6 address plan is available here (Authentication required).

5.2 Examples from Organizations Outside the US

Documents describing Germany’s national IPv6 address plan and its administration are available: DEUTSCHLAND-ONLINE INFRASTRUKTUR IPv6 Reference Manual, and European Governments Enabled with IPv6 (GEN6) IPv6 Addressing Plans.  (The European 6NET project completed Jun 2005. It was followed by the 6DISS project which completed Sept 2007, and then 6DEPLOY and 6DEPLOY-2 (www.6deploy.eu) which completed Feb 2013.) 

Deliverables and Presentations under the Publications tab of the GEN6 website, which completed May 2015, provide additional material. The next European IPv6 project IPv6 Framework for European Governments which completed in 2018 provided examples of address plans as well as planning guidance in Guidelines and Process: IPv6 for Public Administrations in Europe and more generically in the tutorial A National-Level IPv6 Addressing Concept. Then came the European Union Internet Standards Deployment Monitoring project.

6. IPv6 Subnet Planning

Perhaps you need some help with your IPv6 subnet planning. One element of IPv6 address planning that is quite different than it was with IPv4 (and can be hard to understand just how different) is IPv6 subnet planning, as this article explains. Examples of different approaches to IPv6 subnet planning are given in this tutorial and this presentation. This excerpt from a book about IPv6 Address Planning by Tom Coffeen (referenced in part 3 of the IPv6 Training and Learning Information document in the IPv6 Training and Learning article in the Deployment section) discusses IPv6 subnet planning in detail. Best practices for IPv6 subnetting are given by these Best Current Operational Practices (BCOP) and Best Current Practices articles (these articles are quite similar but each provides a few additional pointers), as well as by this Réseaux IP Européens (RIPE) Network Coordination Centre (NCC) RIPE-690 IPv6 prefix assignment for end-users BCOP article. IETF RFC documents (RFC 3531 and RFC 5375) provide in-depth technical recommendations. This article provides a useful perspective on IPv6 subnet planning, plus pointers to some tools, while this article describes IPv6 subnet planning for Linux systems.

7. Tools That May Help

Each tool is a little different, so review the references below to see if one of them does what you are seeking.