Subject: Re: draft-dnsext-edns1-04.txt

From: Paul Vixie <[email-masked]>
Date: Thu, 05 Sep 2002 08:20:09 +0000

> > I think multiple queries is a good idea, if we can work out all
> > the corner cases.
> 
> Agreed.

gentlemen, thank you for those affirmations, let's keep pushing EDNS1 then.

i'll ask eric to find an intermediary -- rob a. would be ideal -- to try
to collate and communicate his (eric's) concerns, since i'm having a LOT
of trouble digesting them directly.

> And there are a couple of 90% answers to the initial-overhead problem:

i thought that kre's analysis of this was on point -- there is no problem.

>   1. Wait a few years before taking advantage of multiple queries on a
> large scale.  Most name servers will have upgraded for other reasons.

i wish that i agreed with that second sentence, but the surveys still show
an awful lot of bind4.8.1 servers out on the net, plus others more recent.

>   2. Cache (by IP address) whether a name server supports EDNS1. 
> Particularly at the stub resolver, this can effectively reduce the
> overhead.

this is mentioned, obliquely, in EDNS0:

   5.3. Responders who do not understand these protocol extensions are
   expected to send a response with RCODE NOTIMPL, FORMERR, or SERVFAIL.
   Therefore use of extensions should be ``probed'' such that a responder
   who isn't known to support them be allowed a retry with no extensions if
   it responds with such an RCODE.  If a responder's capability level is
   cached by a requestor, a new probe should be sent periodically to test
   for changes to responder capability.

i think this is the part rob a. had trouble with, that begat edns0.5.

--
to unsubscribe send a message to [email-masked] with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/namedroppers/>