Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!ucsd!ucbvax!NSIPO.NASA.GOV!medin
From: medin@NSIPO.NASA.GOV ("Milo S. Medin", NASA ARC NSI Project Office)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Can subnets be separated by another net?
Message-ID: <9007101815.AA02883@cincsac.arc.nasa.gov>
Date: 10 Jul 90 10:15:10 GMT
References: <1990Jul10.003628.5859@spectrum.CMC.COM>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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Lars, you are quite correct that use of non-contiguous subnets should
be with good reason.  In many cases, you can do something architecturally pure,
and avoid kludging, which is always a good idea.  But, there are valid
cases to do non-contiguous subnets as well.  As usual, the reason you need
really smart people is to tell the difference between the  cases.  I don't
think that the issue of older protocols not supporting such a configuration is
an issue.  Time moves on, and progress gets made.  In my environment, new
capabilities are eagerly received, and put to good use right away, because
we tend to operate close to the edge of the envelope anyway.  And of course,
at that point, the market tends to demand these new capabilities, and 
people implement them to be competitive.

Your case about the business with the disjoint offices all wanting
their own Internet interconnects while still using a single class B won't
work, but not because of OSPF, but because that organization's connections
to the various regional or brand X networks and those net`s connections to
each other typically use EGP, which does not allow the passing of 
subnet data.  If everyone was glued together by one supernetwork, all
running an IGP like OSPF, then yes, it could work.  But that's not
likely to be the way people's connections would work in any case.

					Thanks,
					   Milo