Subject: (ngtrans) Re: Joint DNSEXT & NGTRANS agenda

From: "D. J. Bernstein" <[email-masked]>
Date: 3 Aug 2001 16:01:23 -0000

Greg Hudson writes:
> That sounds like a loop to me.

It isn't. Here's what the isc.org server does:

   1. Look up isrv4.pa.vix.com.
   2. Set up ftp.isc.org with the same information.

See? No loop. The procedure is guaranteed to end in two steps. The
ftp.isc.org information at any moment is a correct copy of the recent
isrv4.pa.vix.com information, exactly as specified. It doesn't matter
where the isrv4.pa.vix.com information comes from.

---Dan

---

From: Greg Hudson <[email-masked]>
Date: Thu, 02 Aug 2001 11:51:15 -0400

> Wrong. Server-side indirection never causes loops. You would
> understand this if you read my web page:
> http://cr.yp.to/djbdns/killa6.html

I read your web page (just now) and I don't understand that
server-side indirection never causes loops.  Before the isc.org server
can serve the address of ftp.isc.org, it has to have looked up the
address of isrv4.pa.vix.com.  If the pa.vix.com server is
misconfigured and has a "server-side cname" pointing back to
ftp.isc.org, it could be unable to serve the isrv4.pa.vix.com address
before looking up the address of ftp.isc.org.  That sounds like a loop
to me.  The two servers might detect the loop and behave
intelligently, but so can a client.