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From: DCP@QUABBIN.SCRC.SYMBOLICS.COM (David C. Plummer)
Newsgroups: mod.protocols.tcp-ip
Subject: how to make use of redundant routes
Message-ID: <870120145836.3.DCP@KOYAANISQATSI.S4CC.Symbolics.COM>
Date: Tue, 20-Jan-87 14:58:00 EST
Article-I.D.: KOYAANIS.870120145836.3.DCP
Posted: Tue Jan 20 14:58:00 1987
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    Date: Tue, 20 Jan 87 01:07:40 est
    From: hedrick@topaz.rutgers.edu (Charles Hedrick)

    I'd be curious to hear comments from places that have been using
    dynamic routing for some time.  By the way, I am willing to assume
    that all gateways participate in routing using routed.  (Cisco now
    supports routed.)

Users of the Chaosnet protocol have been using dynamic routing for
nearly 10 years now.  Chaosnet is MIT AI memo number 628.  I think it is
online at MIT someplace, but can't find it.  (Snit: it's always bothered
me that IP didn't address this issue from the start.)

A very brief description of Chaos routing follows, so those wishing to
type D(elete) now can go ahead.

Chaosnet only has 255 subnets (which is a problem for very large
configurations, and therefore this may not prove useful for IP, but I
had ideas back in '81 or so on how to extend this kind of routine to IP.
JNC may remember some of them.)  With only 256 subnets, keeping a full
subnet routing table was not hard.  Periodically (every 15 seconds) a
multiple interface bridge would broadcast a routing packet on each
interface.  The routing packet contained several pairs: a subnet number
and a "cost" to get to that subnet.  Periodically (every 4 seconds) each
machine would increment all costs in the table by 1.  When processing a
routing packet, an entry would get replaced if the cost in the routing
packet is smaller than the cost in the current entry.

If you are interested in my extensions to IP / heirarchical addressing
schemes, I can try to dig them up.