Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!apple!rutgers!cmcl2!phri!roy
From: roy@phri.UUCP (Roy Smith)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: MXing the world
Message-ID: <4118@phri.UUCP>
Date: 14 Nov 89 03:24:03 GMT
References: <2029@cmx.npac.syr.edu> <16300008@uxh.cso.uiuc.edu>
Reply-To: roy@phri.UUCP (Roy Smith)
Organization: Public Health Research Institute, NYC, NY
Lines: 21

In <16300008@uxh.cso.uiuc.edu> carlson@uxh.cso.uiuc.edu writes:
> The DNS doesn't deal with concepts like "nearest"

	But what if it did?  Let's say I'm the DNS server for the .BITNET
domain.  When a request comes in for an MX, I take a look at where the
request came from and use that information to select the proper MX record
to send back.  If I can't figure out which is the best, I send back some
default gateway.  I could even send back the same set of MXers to
everybody, but with customized priorities.

	That's not how DNS is supposed to work, but how could an outside
entity detect that I'm doing something fishy?  The fact that repeted
requests don't give back the same answer is in itself not a protocol
violation; what's to keep me from changing my master file every 10 seconds
if I wanted to, and how could you tell the difference between a quickly
changing master file and a routing DNS server?
-- 
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
{att,philabs,cmcl2,rutgers,hombre}!phri!roy -or- roy@alanine.phri.nyu.edu
"The connector is the network"