Question on address configuration

[Pekka Savola]

On Wed, 9 Jan 2002, Matthew Lehman wrote:
> What about a well-known anycast address for the DNS server to listen on.
> The clients could use the well-known address and would only require
> configuration once, it's reasonably scalable (just add more DNS servers
> listening on the address), and it does not require any special changes
                                                     ^^^^^^^^^^^^^^^^^^^
> to any protocols.
  ^^^^^^^^^^^^^^^^

Are you sure about this?  This is different from IPv4 "anycast".  IPv6 
anycast address cannot be used as a source address.  Therefore, according 
to e.g.:

draft-ietf-ipngwg-ipv6-anycast-analysis-00.txt

many DNS implementations may check the source address of the replies to 
the queries; thus use of anycast in this scenario might require 
protocol/implementation changes.

> It does require anycast listening support and I don't
> know of any platforms that currently have it.  Someone on the list might
> know more about implementations in the works.

Anycast Listening is not a problem, e.g. KAME/BSD have had it for a long 
time now, USAGI for Linux just got it.

FWIW, I've used IPv6 anycast address for about half a year in a 6to4 relay
setup.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords