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From: oleary@sura.net (dave o'leary)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: backplane backbone, routing or bridging?
Message-ID: <1991Jun26.013335.25835@sura.net>
Date: 26 Jun 91 01:33:35 GMT
References: <9106250555.AA23713@wolf.cisco.com>
Organization: SURAnet, College Park, MD
Lines: 37

In article <9106250555.AA23713@wolf.cisco.com> satz@cisco.com (Greg Satz) writes:
>>> 
>>> I'll point out that you don't need OSI, just OSPF with variable length
>>> subnet mask support in the IP forwarder.  Several vendors already do this.
>>> It's not rocket science, and routing technology has surpassed the 
>>> point where such restrictions are required.  Subnets no longer need to
>>> be connected if you do things right.
>>> 
>>> 						Thanks,
>>> 						   Milo
>
>Milo, when is the IETF going to write up how variable length subnet masks
>should be used? There are a number of situations where unexpected behavior
>can occur. Is everyone expected to learn this for themselves?
>
>Greg

Greg et al,

I'm working on article for the SURAnet newsletter (which I will finish 
any month now) on packet forwarding decisions in a subnetted environment.
When I have a reasonable draft done, I can make it available for 
interested parties to check out.  In particular I am addressing the 
issues of limitations of the forwarding table without subnet masks, 
how to kludge around this under special conditions and why that is 
dangerous, and how things work in a variably-subnetted environment
(using SURAnet, with lots of point to point and a couple of bigger
ethernets as an example), and how and why non-connected "subnets"
(which aren't really subnets anymore) can still see each other in 
the new world order without Class A, B, and C.  Is there anything 
else that should be covered to make this comprehensive?  I'm more than 
half done at this point, but some of the hairier points remain to be 
covered.  Is this the kind of document that you are interested in?

Thanks,

					dave