Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ucbvax!THUMPER.BELLCORE.COM!tsuchiya
From: tsuchiya@THUMPER.BELLCORE.COM (Paul Tsuchiya)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Help designing address allocation in a metronet
Message-ID: <9103221517.AA26126@chiya.bellcore.com>
Date: 22 Mar 91 15:17:47 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 34

> 	Another argument for OSPF, which is link state and not
> distance vector.  Milo Medin has documentary evidence of reduced
> routing bandwidth in the NASA internet to prove that link state is
> better in this regard.
> 

Sorry Kent.  I know this is a REAL nit, but you hit
on one of my pet peeves.  The advantage of OSPF over RIP
in the case of link utilization is not that OSPF is
link-state and RIP is distance-vector, but that OSPF
is event-driven and RIP is periodic.  One can perfectly
well design a distance-vector routing protocol (BGP
for instance) that is event-driven and therefore doesn't
over-utilize link bandwidth.  CA*net is running BGP
over 56kbps links, and advertising ALL 2000+ network
numbers, and is not having problem (except for 
spikes when a router configures because the whole
routing table gets dumped).

That being said, I think that link-state does have
advantages over distance-vector (like ease of debugging
because the whole topology map is right there in
every node), but distance-vector also has certain
advantages over link-state, like dealing with hierarchies
because you don't have the mapping real topology
into logical topology problem that results in things
like pseudo-nodes.

Lecture over :-)

PT
NAADP
(National Association for the Advancement of
Distance-vector Protocols)