York - Migrating Applications to IPv6

• IPv4 address exhaustion is getting closer . In February 2011, the Internet Assigned Numbers Authority (IANA) allocated the last IPv4 address blocks out to the Regional Internet Registries who ultimately distribute IPv4 addresses to Internet service providers (ISPs) and end users. There simply are no more IPv4 addresses to distribute. Now, the RIRs do have existing pools of IPv4 addresses that may in fact last for a few more years, but very soon the options will be increasingly limited and more and more networks will be looking to IPv6 as the solution to bring more devices and users online.

• World IPv6 Launch is happening on June 6, 2012 . On that date (and potentially before), IPv6 will be permanently enabled for many websites by more ISPs and by many home router vendors. Major websites and services such as Google, Facebook, Yahoo, YouTube, Netflix, and more will be permanently accessible over IPv6. Very large ISPs have committed to providing IPv6 connectivity to a larger percentage of their customer base. There will be more end users out there using IPv6and more cases where your application may not work if it doesn't work well with IPv6.

• The Internet Engineering Task Force (IETF) has specified that IPv6 is no longer considered optional . RFC 6540, IPv6 Support Required for All IP-Capable Nodes , issued in April 2012, states very explicitly that IPv6 can no longer be considered optional and that all nodes connected to IP networks need to support IPv6. While this RFC cannot be directly enforced with todays networks, it does provide a clear direction for implementors to move and also firmly indicates that future IETF standards will require IPv6. You will need to work with IPv6 for your application to work in future networks.

• Your application may not work or may suffer performance degradations with IPv4 extension technologies . There are a number of technologies being considered by service providers and enterprises to extend the life of IPv4 addresses and delay the need to move to IPv6. One of the major techniques being considered is called Carrier Grade Network Address Translation (NAT)" or CGN. CGN is basically the idea of using a second layer of NAT at the ISP level to hide an entire ISP's network behind a single public IPv4 network. However, the problem is that some applications, particularly those that use real-time communications or are sensitive to latency, may not work at all or may suffer serious performance degradation when used behind CGN. A recent presentation at the 2012 North American IPv6 Summit documented some research into this issue. In many cases, applications that work over native IPv6 networks worked fine while IPv4-only applications suffered these performance issues.

Are you an application developer? A product manager? A product marketing manager? A documentation author? A training instructor? A system/network architect? This book is designed to help you understand what issues you need to explore with your application.

Developers, you will come away with enough information to go through your application and make the necessary changes. Product managers, you will gain an understanding of what points you need to considerand what you need to ask of your technical teams. If you are in marketing, documentation, or training, you will get a good sense of what youll need to think about changing in your materials. And if you are a system/network architect looking at your overall IPv6 implementation, you should leave with a better sense of what changes may need to be considered across the applications that are deployed in your infrastructure.