Transitioning from IPv4 to IPv6 is looming, and devising an IPv6 migration plan is vital for companies to maintain customer productivity. This IPv6 migration guide provides the essentials for businesses to understand the migration from IPv4 to IPv6 and the importance of devising an IPv6 migration plan. It will also help them understand Ipv6 addressing, and know plan pitfalls and best solutions to overcome them.
IPv6 migration guide and planning strategy
The long-awaited demise of the IPv4 address space is imminent. The Internet Assigned Numbers Authority (IANA) allocated its last remaining blocks of IPv4 address space out to regional registries for distribution a year ago, and the Regional Internet Registry (RIR) for the Asia Pacific region ran out of addresses in April. With the supply of IPv4 addresses dwindling, businesses need to begin planning their IPv6 migration now if they haven’t already done so. This IPv6 migration guide is designed to help you.
The implications of ignoring an IPv6 migration plan
Businesses that delay their IPv6 migration plan put themselves at risk. In the near-term, you run the risk of being unable to communicate with customers. When IPv4 addresses run out, websites with IPv4 addresses will not be accessible. In the long term, you could face more technical work. Users will be forced to go through large-scale NAT appliances, which will degrade their performance on the IPv4-Internet. Multiple layers of NAT for enterprises will cause more complexity and performance degradation. Network engineers could spend a significant amount of their time playing a shell game inside of their companies' networks by taking any public IPv4 address they have and moving it around to applications that need it, and then readdressing it more in the private addressing space.
But that’s not all. Read this article to learn more about why you should prepare for IPv6 now and the implications of putting off your IPv6 migration plan.
Understanding IPv6 addressing
In order to plan an IPv6 migration strategy, you must first understand IPv6 addressing and IPv6 address types. IPv6 addresses are represented as eight chunks of four hex characters. This requires you to rethink how you treat addresses. For example, in the past you may have been frugal in your use of IPv4 addresses due to concerns of scarcity. IPv6 allows you to be more liberal with your addresses.
In IPv6, unicast and multicast addresses function the same way as their IPv4 counterparts. Anycast addresses, however, are new to IPv6. They are shared by multiple nodes. A message sent to an anycast address is sent to only one of the interfaces identified by the anycast address. IPv4-mapped addresses are used to support the IPv4 to IPv6 transition.
IPv6 migration plan basics
There are several steps that every organization should take as part of an IPv6 migration strategy. At the very least, include the following in your plan:
1. Survey equipment vendors and network service providers to understand their IPv6 plans and capabilities. Create a report listing all of your current network infrastructure and their associated capabilities to support IPv6.
2. Find out how your WAN and Internet service providers will support IPv6. Will they provide end-to-end IPv6 tunnels or simply NAT between IPv4 and v6? How will they prioritize various classes of v6-based traffic across v4-based services?
3. Work with developers to evaluate your application portfolio—both off-the-shelf applications and those developed in-house—for IPv6 compatibility.
4. Determine when to build an IPv6 internal network. You may decide to deploy an IPv6 internal network in tandem with an external one to avoid extra costs, or you may decide to wait for a clear business case before deploying an IPv6 internal network.
Pitfalls to avoid in an IPv6 migration plan
A successful IPv6 migration plan requires careful attention to device capabilities, system architecture, scalability, management and provider services. Thus, be careful to consider these common IPv6 migration pitfalls:
- Hardware or software? High-capacity core routers typically process packets in dedicated hardware to speed IPv4 forwarding. However, hardware architectures that don’t support IPv6 process packets in general purpose processors result in slower forwarding rates and lower capacity.
- Applications. Some applications, like those using the Session Initiation Protocol (SIP), care about the Internet Protocol of the underlying network. In this case, vendors and developers of SIP-based applications must reconfigure their apps to support IPv6 information in the SIP header.
- Carriers. Support for IPv6 is still very limited, especially for services such as MPLS and residential Internet.
- Multi-homing and private addressing. Creating a multi-homing or v6 NAT strategy requires close coordination with your service providers and possibly obtaining your own IPv6 address space.
- Everything else. Analyze your WAN optimization and management platforms, provisioning and change management applications, sensors and M2M devices, and management tools for their ability to support IPv6.
Learn more about these IPv6 planning pitfalls.
If all else fails, consider professional services
Taken as a whole, this IPv6 migration guide should serve as a reminder that implementing IPv6 requires a great deal of advanced planning. WAN service providers are ready to help—for a price, of course. If you have a relatively small number of public IP addresses to migrate or plan to limit migration to a handful of servers, then experts agree you probably don’t need professional services—at least for the time being. However, if you have a large migration or wait too long to begin migrating, professional consulting services may be worth the money.
This article explores IPv6 migration services in more detail, including providers offering these services.
This was first published in June 2011