- From: Edward Lewis <edlewis@arin.net>
- Date: Fri, 6 Dec 2002 08:48:20 -0500
- To: Dave Crocker <dcrocker@brandenburg.com>, Edward Lewis <edlewis@arin.net>
- Cc: discuss@apps.ietf.org
At 22:35 -0800 12/5/02, Dave Crocker wrote: >Sounds like you are tripping across the end-to-end myth. Whenever we design >a protocol that believes there is a direct interaction between one end-point >and the other, we later have to deal with the presence of intermediation. >Caches. Firewalls. Whatever. > >Store-and-forward is not just for layer 3. I'm not sure if I agree or disagree. Yes, I'm tripping over an end-to-end assumption made in the protocol, but I don't get the 'myth' part. You describe the problem nearly dead on. When using the existing cache mechanisms in DNS, they can become an obstacle if an old version is not compatible with a new feature. With end-to-end being a possibility, I could 'route around' the cache - this is possible in the protocol. But when end-to-end is not possible, as in the case of a NAT bottlenecking all traffic, then I can't route around the old cache. Designing DNS to be tolerant of NATs is a pain, as Keith alludes to in a previous message. It's remotely possible, but a real waste of time and energy. Just as other applications want to mimic DNS's recursive lookup behavior (which is a mistake), DNS shouldn't turn around and mimic store and forward behavior of its messages. The rat holes are already known, fortunately no one is trying to measure their depth. ;) -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Edward Lewis +1-703-227-9854 ARIN Research Engineer
Received on Friday, 6 December 2002 09:18:19 UTC