To:
Paul Vixie <vixie@vix.com>
Cc:
dnsop@cafax.se
From:
Brad Knowles <brad.knowles@skynet.be>
Date:
Wed, 26 Feb 2003 14:36:35 +0100
In-Reply-To:
<g3u1et9oda.fsf@as.vix.com>
Sender:
owner-dnsop@cafax.se
Subject:
Re: wrong file name, late by a day, but here it aspromised: respsize.txt
At 12:48 AM +0000 2003/02/25, Paul Vixie wrote:
> With a mandated default minimum maximum of 512 octets, the DNS
> protocol presents some special problems for zones wishing to
> advertise moderate or high numbers of authority servers (NS RRs).
> This document explains the operational issues caused by or related to
> this response size limit.
Hmm. Back in '97 (I think), there was a draft that was created
on pretty much the same topic. This was right after the 19-hour
downtime at AOL, and where much of the Internet was unable to send
e-mail because we were advertising too many MXes (45?), and combined
with the two minute TCP timeout and typical queue runner startup
times (every sixty minutes), many sites would stack up queue runners
until they ran out of memory (real & virtual) and the server would
crash. These queue runners would get a timeout on each of the
advertised MXes, and not be able to process any other mail while
sitting and spinning their wheels.
However, that draft ultimately died. Both qmail and postfix
should avoid excessive problems of this sort, and intelligent
installations of sendmail should avoid problems of this sort, but I'm
sure that there are plenty of sites out there that are still
vulnerable to this sort of thing.
Would it be possible to incorporate some analysis and
recommendations on this issue in future versions of this draft?
--
Brad Knowles, <brad.knowles@skynet.be>
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
-Benjamin Franklin, Historical Review of Pennsylvania.
GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
!w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)
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