11.1 Introduction

IPv6 is tomorrow's internetwork protocol -- perennially, it seems. BIND has supported IPv6 forward and reverse-mapping since Version 4.9.5, released way back in 1996. BIND 9, finally, added support for IPv6 as a transport, responding to queries received over IPv6.

The IETF -- the body that develops extensions to DNS, among other things -- briefly flirted with a very complex method of handling IPv6 forward and reverse-mapping, using A6 and DNAME records and "bitstring labels." (Unfortunately, I wrote the fourth edition of DNS and BIND at just the wrong time and documented A6 and the rest.) Eventually, however, they opted to standardize on a system that uses AAAA and PTR records in a straightforward way, similar to the way A and PTR records work with IPv4 addresses.