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From: brescia@CCV.BBN.COM (Mike Brescia)
Newsgroups: mod.protocols.tcp-ip
Subject: Re: EGP madness (net 127)
Message-ID: <8611140205.AA00319@ucbvax.Berkeley.EDU>
Date: Thu, 13-Nov-86 16:20:28 EST
Article-I.D.: ucbvax.8611140205.AA00319
Posted: Thu Nov 13 16:20:28 1986
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>          Some of you may be interested in the following EGP topology, which I got
>     back from my favorite gateway, 10.1.0.15.  Note that 10.2.0.80 thinks that
>     network 127 is 3 hops away.  What the hell is network 127???

Net 127, an unregistered net number, is used by Berkeley in the 4.xBSD unix to
indicate the 'loopback interface' internal to the host.  It has in the past
been advertised by some hosts which run EGP and accidently have the loopback
address listed first in the configuration of the net interfaces in the unix.

It is happening again at NLM-MCS.

The 'core' system, while providing some protection to itself, does not censor
any information, but passes this on to the other gateways, and thus to the
other EGP sites.  It probably causes a bit of confusion on any vaxes which run
EGP and are trying to use their own loopback interface.

(I've deliberately tried to eschew any biased statements above, but had to get
this self-referent, biased sentence in.)

    Mike Brescia
    Gateway Censor.