Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!know!pluto.hemel.bull.co.uk!pmoore
From: pmoore@hemel.bull.co.uk (Paul Moore)
Newsgroups: comp.protocols.tcp-ip.domains
Subject: Re: problems with nsfnet-relay.ac.uk
Message-ID: <1991Feb27.122824.28436@hemel.bull.co.uk>
Date: 27 Feb 91 12:28:24 GMT
References: <1991Feb22.181958.14608@ns.uoregon.edu> <75539@bu.edu.bu.edu> <1991Feb26.192433.25943@nstn.ns.ca>
Organization: Bull HN UK
Lines: 25

I reckon the problem is a policy change in nsfnet.
Doing telnet nsfnet...... gets in OK
Doing telnet nsfnet... 25 times out. This does not mean nobody is listening
on port 25. If this was the case the connect would be reject straight away.
(try doing telnet xxxx 1234 , or 25 on a machine with no smtp daemon). The
fact that the connect to a specfic port times out shows that some filtering
in being done on the basis of dest port number, probably by a router in
front of nsfnet-relay.

Plus , the MX records for *.ac.uk say go to nsfnet-relay but the MX records
for *.co.uk say go to mcsun.

The problem is that of .com (or .co.uk on the Internet) trying to send to
.ac.uk sites I guess.

There was some flaming inside UKnet about people routing mail via nsfnet
saying "this is an acedemic only net - commercial orgs must not use it". But
when somebody pointed out that their MX records routed mail to nsfnet I 
thought that would be the end of - I guess not.

-- 
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! Paul Moore, Bull HN UK, Maxted Rd,Hemel Hempstead, HP2 7DZ.   !
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! pmoore@hemel.bull.co.uk     "a smile, a song and a core dump" !
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