DNS and BIND on IPv6

Chapter 1. DNS and IPv6

Background

In early February 2011, the Internet Assigned Numbers Authority, or IANA, assigned the last remaining IPv4 address space to the five Regional Internet Registries (RIRs). As of this writing, the RIRs haven’t yet doled out that address space to carriers and other customers, but it’s clear that the exhaustion of IPv4 address space is imminent.

For most organizations on the Internet, the depletion of the Internet’s unallocated IPv4 address space won’t necessitate immediate changes—IPv4 isn’t going anywhere for the foreseeable future. In certain exceptional cases, however, organizations may need to implement IPv6 almost right away: mobile carriers and ISPs seeking to expand their subscriber bases, for example, may need to use IPv6 for new subscribers if they lack additional IPv4 address space to use for expansion.

The Internet’s transition from IPv4 to IPv6 has begun. With the US government’s mandate that government agencies move their networks to IPv6, a growing number of users will access the Internet over the new protocol, and an increasing number of resources—websites, name servers, mail servers, and more—will be accessible via IPv6. In some cases, some may only be accessible over IPv6.

The transition to IPv6 will take years, maybe decades, to complete. Today, of course, IPv6 is already routed over the Internet: 9% of the Internet’s Autonomous Systems advertise routes to both IPv4 and IPv6 networks. But IPv6 constitutes a tiny fraction of the traffic ...