Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!rutgers!bellcore!ka9q.bellcore.com!karn
From: karn@ka9q.bellcore.com (Phil Karn)
Newsgroups: comp.dcom.lans
Subject: Re: Problems finding forwarding tables on LAN Bridges
Keywords: bridge
Message-ID: <13791@bellcore.bellcore.com>
Date: 2 Feb 89 04:47:09 GMT
References: <917@cernvax.UUCP> <13701@bellcore.bellcore.com> <921@cernvax.UUCP>
Sender: news@bellcore.bellcore.com
Reply-To: karn@ka9q.bellcore.com (Phil Karn)
Organization: Secular Humanists for No-Code
Lines: 16


Yes, the "topology file" contains a list of Lan Bridge ethernet addresses
and the identities of the cable segments attached to their A and B ports.

The only real problem I've encountered in practice is LAN bridges that have
been switched off or disconnected; the result is a non-unique answer (i.e.,
more than 1 possible location).  It can take a bit of work to keep the
topology file up to date when you have a large network.  But it has already
helped us find some misbehaving hosts very quickly. I only wish it was as
easy to figure out which host (out of several in locked labs or offices) on
a given segment is the offender!

The software, by the way, runs on a Sun workstation under SunOS 3.x; it uses
the NIT(4) raw packet facility. I'm inquiring about how I might release it.

Phil