Path: utzoo!attcan!uunet!husc6!bloom-beacon!apple!bionet!agate!ucbvax!XX.LCS.MIT.EDU!SRA
From: SRA@XX.LCS.MIT.EDU (Rob Austein)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Network Connectivity - Part 2
Message-ID: <12443906829.34.SRA@XX.LCS.MIT.EDU>
Date: 4 Nov 88 17:41:47 GMT
References: <12443864209.25.AI.CLIVE@MCC.COM>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 23

Clive,

Right.  Here's the rest of the story.  XX and Score are configured
differently than MCC or NIC, because while all four are multi-homed
hosts, XX and Score are not the sole contact points between the nets
to which they are connected.  Eg, XX is connected to nets 10 and 18,
but so is GW.LCS.MIT.EDU.  A multi-homed TOPS-20 in this configuration
needs more entries in its INTERNET.GATEWAYS file than just its IMP's
two assigned "mailbridge" gateways, eg, XX's also lists GW,
KLUDGE.AI.MIT.EDU, SLUDGE.LCS.MIT.EDU, and SEWAGE.MIT.EDU.  Yesterday
XX ended up routing all of its "default" traffic via GW.LCS.MIT.EDU
after it gave up on IMP44's assigned gateways.  I assume something
similar happened to Score.

Is the "eager pinger" problem believed to be fixed?  If I remember
correctly, that's where the practice of having only two live core
gateways known per host came from.  The NIC has a file online (in
NETINFO:, I think) explaining this, but it was never clear to me if
the underlying problem was really fixed or simply toned down to an
acceptable level if everybody stuck to the two gateway rule.

--Rob
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