Home | Background | Mapping | Enabling | Awareness | Infrastructure | Standards | Contact IPv6logo

Activity 2.3 Transition Checklist

*NEW* IPv4 Countdown Policy Proposal

Geoff Huston's research at Potaroo (http://www.potaroo.net/tools/ipv4/) projects the date of exhaution of unallocated IANA IPv4 addresses as mid-2011, and that of the Regional Registry pool as mid-2012, and Tony Hain finds similar dates based on a different algorithm. If the current allocation trend continues, the exhaustion of IPv4 address space will to take place within the next five years. Below is a proposal to respond in an orderly way to this potentially difficult situation:

A. Steps for Successful Deployment

Every business needs to decide for itself the timing and sequence of a transition to IPv6. Below are some steps that will help in successful deployment. Note that the actual phasing-in of IPv6 equipment is only one of them - most steps refer to strategic decisions and activities that need to take place across the entire organisation, not just in the technical area.
  1. Assess business requirements, risks and benefits
  2. Survey existing network infrastructure
  3. Educate technical staff professionally
  4. Resource network and security infrastructure
  5. Phase-in and test IPv6-capable devices
  6. Inform and set policies for general staff
  7. Monitor and maintain procedures and infrastructure

1. Assess business requirements, risks and benefits

  • At the highest level of the business, large or small, discuss the future of the business in relation to the risks and benefits that could arise from deploying IPv6.
  • Work through the Busines Case scenarios discussed on this site. Identify quantitative and qualitative reasons for transitioning to IPv6 that are relevant to business requirements, evolution and program activities.
  • Solicit ideas across the whole of the enterprise, as benefits and risks of IPv6 are often not simply technical - for instance, there may be stock control or marketing possibilities.
  • Estimate the benefits and risks with the ROI Evaluator, to calculate net present value, return on investment, and payback period involved in implementation of a well-defined project, and derive benchmarks that can be refined through experience.
  • Set up a Transition Group or centralised body, with the backing of the highest levels of management, to plan, coordinate and communicate the progress of IPv6 deployment. The group should have representation from all affected areas of the enterprise.

2. Survey existing network infrastructure

  • Technical staff should systematically survey and catalogue all aspects of the system, such as applications, computers and networks that may be affected by IPv6 deployment (as with Y2K efforts).
  • Begin the planning process as soon as possible, as a careful implementation over a long period of time will be more cost-effective and less disruptive than a last-minute rush job.
  • Discuss with vendors their state of IPv6 readiness, and your future requirements for IPv6-capable equipment. Revisit and adjust your requirements at frequent intervals.

3. Educate technical staff professionally

  • Network problems can have significant effects upon your business functioning and credibility, so budget for professional education for technical staff.
  • Send system and network staff to appropriate training, conferences and meetings, and subscribe to and circulate IPv6 books and magazines.
  • Encourage technical staff to monitor activity of IPv6 standards groups, join relevant Internet mailing-lists, and become involved generally in IPv6 development.
  • Require IPv6 and other relevant technical training to be an ongoing aspect of career advancement within the organisation.

4. Resource network and security infrastructure

  • Appreciate that for IPv6 to succeed it must be deployed with care and thoroughness, which have innate costs in time and effort.
  • Like all applications, IPv6 can lead to vulnerabilities in functionality and security, so provide appropriate levels of human and technical resources.
  • Regard transition planning and deployment activities as a budget saver, because lack of sufficient resources will have costly impacts on business viability and staff morale.
  • Begin migrating staff focused on solving problems in IPv4 to solving them in IPv6. Voice over IP (VoIP), convergence and QoS are examples where R&D resources could be reallocated to IPv6 projects.

5. Phase-in and test IPv6-capable devices

  • During normal infrastructure upgrade cycles buy equipment that is already IPv6-capable. IPv4-only equipment will quickly become obsolete and have little future value.
  • Plan and implement a non-disruptive transition - start with a pilot project to test IPv6 on existing IPv4 networks, which will also develop the experience of technical staff.
  • Then run separate IPv4 and IPv6 networks in the organisation - select a specific application or sub-network appropriate for full IPv6 functionality. It will require its own routers and security infrastructure.
  • Over time, transition the whole network to 'dual-stack' routers and security infrastructure, capable of handling both protocols.
  • Eventually move completely to a native IPv6 network, carefully phasing out legacy IPv4 applications.

6. Inform and set policies for general staff

  • In some aspects IPv6 offers end-users greater control over their computing and network resources, which may or may not suit business requirements.
  • General staff must be educated about IPv6 implications, organisational policy and any enforcement procedures.
  • IPv6 policies should be released and emphasized on a timely basis, and integrated into existing procedures for review and enforcement.
  • Staff must also be kept informed of the progress of development, changes to the network and any potential effects such as downtime.

7. Monitor and maintain procedures and infrastructure

  • Develop metrics to provide senior management with information on the value and progress of the IPv6 transition in areas such as strategy, management, technical processes, staff education, schedules and phases of the transition.
  • Assist staff to understand and adhere to resource and security policies.
  • Invest in ongoing technical staff development, equipment maintenance and system security infrastructure.
(Some of the above points were drawn from an article by Tom Kreidler, Juniper Networks.)

B. Information Resources

Here are some useful resources to assist with the steps above:

C. IETF Guides to IPv6 Deployment

All Internet functionality derives originally from the work of the Internet Engineering Task Force which defines the fundamental standards and protocols. Work on IPv6 began in the mid 1990s and is continuing, see our page on IPv6 Standards and Working Groups.

The IETF has produced some valuable documents on transition techniques for different types of network, some of which roughly correspond to our Mapping categories Large Enterprise, Small Business, and Home Office.

Small Business and Home Office Networks
RFC 3750 - Unmanaged Networks IPv6 Transition Scenarios
C. Huitema, R. Austein, S. Satapati, R. van der Pol [April 2004]

This document defines the scenarios in which IPv6 transition mechanisms are to be used in unmanaged networks. In order to evaluate the suitability of these mechanisms, we need to define the scenarios in which these mechanisms have to be used. One specific scope is the "unmanaged network", which typically corresponds to a home or small office network. The scenarios are specific to a single subnet, and are defined in terms of IP connectivity supported by the gateway and the Internet Service Provider (ISP). We first examine the generic requirements of four classes of applications: local, client, peer to peer and server. Then, for each scenario, we infer transition requirements by analyzing the needs for smooth migration of applications from IPv4 to IPv6.

RFC 3904 - Evaluation of IPv6 Transition Mechanisms for Unmanaged Networks
C. Huitema, R. Austein, S. Satapati, R. van der Pol [September 2004]

This document analyzes issues involved in the transition of "unmanaged networks" from IPv4 to IPv6. Unmanaged networks typically correspond to home networks or small office networks. A companion paper analyzes out the requirements for mechanisms needed in various transition scenarios of these networks to IPv6. Starting from this analysis, we evaluate the suitability of mechanisms that have already been specified, proposed, or deployed.

Large Enterprise Networks
RFC 4057 - IPv6 Enterprise Network Scenarios
J. Bound, Ed. [June 2005]

This document describes the scenarios for IPv6 deployment within enterprise networks. It defines a small set of basic enterprise scenarios and includes pertinent questions to allow enterprise administrators to further refine their deployment scenarios. Enterprise deployment requirements are discussed in terms of coexistence with IPv4 nodes, networks and applications, and in terms of basic network infrastructure requirements for IPv6 deployment. The scenarios and requirements described in this document will be the basis for further analysis to determine what coexistence techniques and mechanisms are needed for enterprise IPv6 deployment. The results of that analysis will be published in a separate document.

RFC 4554 - Use of VLANs for IPv4-IPv6 Coexistence in Enterprise Networks
T. Chown [June 2006]

Ethernet VLANs are quite commonly used in enterprise networks for the purposes of traffic segregation. This document describes how such VLANs can be readily used to deploy IPv6 networking in an enterprise, which focuses on the scenario of early deployment prior to availability of IPv6-capable switch-router equipment. In this method, IPv6 may be routed in parallel with the existing IPv4 in the enterprise and delivered at Layer 2 via VLAN technology. The IPv6 connectivity to the enterprise may or may not enter the site via the same physical link.

Internet Service Provider Networks
RFC 4029 - Scenarios and Analysis for Introducing IPv6 into ISP Networks
M. Lind, V. Ksinant, S. Park, A. Baudot, P. Savola [March 2005]

This document describes different scenarios for the introduction of IPv6 into an ISP's existing IPv4 network without disrupting the IPv4 service. The scenarios for introducing IPv6 are analyzed, and the relevance of already defined transition mechanisms are evaluated. Known challenges are also identified.

Transition Techniques
RFC 4213 - Basic Transition Mechanisms for IPv6 Hosts and Routers
E. Nordmark, R. Gilligan [October 2005]

This document specifies IPv4 compatibility mechanisms that can be implemented by IPv6 hosts and routers. Two mechanisms are specified, dual stack and configured tunneling. Dual stack implies providing complete implementations of both versions of the Internet Protocol (IPv4 and IPv6), and configured tunneling provides a means to carry IPv6 packets over unmodified IPv4 routing infrastructures.

RFC 4192 - Procedures for Renumbering an IPv6 Network without a Flag Day
F. Baker, E. Lear, R. Droms [September 2005]

This document describes a procedure that can be used to renumber a network from one prefix to another. It uses IPv6's intrinsic ability to assign multiple addresses to a network interface to provide continuity of network service through a "make-before-break" transition, as well as addresses naming and configuration management issues. It also uses other IPv6 features to minimize the effort and time required to complete the transition from the old prefix to the new prefix.

RFC 4038 - Application Aspects of IPv6 Transition
M-K. Shin, Ed., Y-G. Hong, J. Hagino, P. Savola, E. M. Castro [March 2005]

As IPv6 networks are deployed and the network transition is discussed, one should also consider how to enable IPv6 support in applications running on IPv6 hosts, and the best strategy to develop IP protocol support in applications. This document specifies scenarios and aspects of application transition. It also proposes guidelines on how to develop IP version-independent applications during the transition period.

IPv6 Transition/Co-existence Security Considerations

This is a useful IETF Internet-Draft (work in progress) on the transition from a pure IPv4 network to a network where IPv4 and IPv6 co-exist. It considers security issues in three categories: issues due to the IPv6 protocol itself, issues due to transition mechanisms, and issues due to IPv6 deployment.

Dr Kate Lance
Internet Society of Australia

The IPv6 for e-Business project is supported by the Australian Government through the Information Technology Online (ITOL) Program of the Department of Communications, Information Technology and the Arts.