Re: A6/DNAME usage guidelines and limits

"D. J. Bernstein" <djb@cr.yp.to> Sun, 07 April 2002 07:42 UTC

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Date: Fri, 05 Apr 2002 22:47:37 -0000
From: "D. J. Bernstein" <djb@cr.yp.to>
To: namedroppers@ops.ietf.org
Subject: Re: A6/DNAME usage guidelines and limits
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[ post by non-subscriber ]

Carl Perry writes:
> A6 is a good idea, in general.

No, it isn't. See http://cr.yp.to/djbdns/killa6.html. The problems with
A6 are much bigger than the cost of an extra loop in (stub) clients.

The fundamental problem is that A6's cross-server indirection is being
performed in the foreground instead of in the background. We already
have reliability problems from foreground cross-server indirection in NS
and CNAME, even though NS and CNAME don't _encourage_ cross-server
indirection the way that A6 does.

For people who want separate signatures on chunks of an address: Fine.
Put separate signatures on chunks of an address. This is compatible with
background indirection.

---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago


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A6/DNAME usage guidelines and limits Nathan Jones
Re: A6/DNAME usage guidelines and limits Carl Perry
Re: A6/DNAME usage guidelines and limits D. J. Bernstein
Re: A6/DNAME usage guidelines and limits Carl Perry
Re: A6/DNAME usage guidelines and limits Paul Vixie