A6/DNAME not needed for v6 renumbering [Re: who gets a /32 [Re: IPV6 renumbering painless?]]

Paul Vixie paul at vix.com
Sun Nov 28 18:56:50 UTC 2004


> [...]
> 
> Isn't about the same achievable with about two or three lines of
> scripting (or a new zone parsing option for bind ;) with a lot less
> protocol complexity?

only if you can tolerate short TTL's on all your AAAA's.  in the A6/DNAME
model, your A6's could have long TTL's whereas your DNAME's could have
short(er) ones.

> As you note, A6/DNAME wasn't a panacea.  A lot additional stuff is
> needed to achieve the goal.  It seems to me that actually the A6/DNAME
> part is a relatively simple one to achieve using current mechanisms.

the other issue is multihoming.  someone who got done traversing the maze
of A6 and DNAME RRs that it took to find your addresses would pretty much
know that you were supernetting at the LAN level and that they should use
a very short timeout when connecting to each address.  when someone gets
back multiple AAAA's for you, then you might be multihomed, and folks will
do just what they do with multiple A's, which doesn't support rapid
renumbering.



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