In her review of "draft-ietf-ipv6-unique-local-addr-03.txt", Margaret raises an excellent point: > (1) This draft doesn't mention the reverse DNS tree. Is it expected that > whatever registry assigns these values will also populate the reverse > DNS tree? Or not?
The registration process could conceivably populate the reverse DNS tree, but that would only be a partial solution: the draft also defines random prefixes that don't need to be registered. Also, there is no requirement that the networks numbered with these unique local addresses be accessible to DNS resolvers on the Internet. We may however want some kind of "theory of operation". When a network is numbered using unique local addresses, hosts in that network will want to resolve addresses to names. There are 2 possible solutions: 1) Add specific knowledge of this reverse tree to the DNS servers in the unique-local-addressed site, 2) Perform reverse name resolution by asking the host itself, sending either a host information query or an LLMNR PTR request to the IPv6 address being resolved. The first solution is similar to the "dual face DNS" deployments common in organization networks, and should probably be the normal case. It does not require registration in the ip6.arpa tree. It does however require some coordination between DNS servers of unique-local-addressed sites when these sites establish a back-door connection. This coordination could be facilitated if we used a conventional host identifier for "the DNS server within a uniquely addressed site". We generally shied away from the second solution, and generally from using the host identification query to provide reverse mappings. Using LLMNR does make sense when LLMNR is also used as the primary name resolution service within the unique-local-addressed site. -- Christian Huitema -------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
