Penguin
Annotated edit history of AAAAvsA6 version 4, including all changes. View license author blame.
Rev Author # Line
4 AristotlePagaltzis 1 For [IPv6] there are two types of [DNS] ResourceRecord, <tt>AAAA</tt> and <tt>A6</tt>.
1 PerryLorier 2
4 AristotlePagaltzis 3 <tt>AAAA</tt> is the simple one -- it works just like an <tt>A</tt> record in [IPv4], but with more bits.
1 PerryLorier 4
4 AristotlePagaltzis 5 <tt>A6</tt> supports fragments of [IPv6] addresses. You can say <tt>example.com</tt> has the fragment <tt>2002:c000:0201</tt>, <tt>engineering.example.com</tt> has "the example.com fragment" + <tt>:0001</tt>, and <tt>foo.engineering.example.com</tt> has "the engineering prefix" + <tt>:0000:0000:0000:0001</tt>. This means that when <tt>example.com</tt> renumbers, they change just the one ResourceRecord for <tt>example.com</tt> and all of their machines have been renumbered.
1 PerryLorier 6
4 AristotlePagaltzis 7 Some people complain that <tt>A6</tt> is too complicated, and prone to problems:
8 * What is the [TTL] on the response if the fragments all have different lifetimes?
9 * What's the status of it if some of the entries (but not all of them) are signed with [DNSSEC]?
10 * What protection is there against [DoS]?
1 PerryLorier 11
4 AristotlePagaltzis 12 The <tt>A6</tt> people say that it's necessary for networks that regularly change [IP] address (eg: networks that use a dynamic 6to4 address).
13
14 <tt>A6</tt> in general is the newer standard, and <tt>AAAA</tt> is the older standard, however, there doesn't yet appear to be much momentum for <tt>A6</tt> support.
1 PerryLorier 15
2 CraigBox 16 -----
3 MikeBeattie 17 CategoryDns