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From: dls@mace.cc.purdue.edu (David L Stevens)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Subnetting
Message-ID: <12@mace.cc.purdue.edu>
Date: 9 May 88 15:34:15 GMT
References: <8805090727.AA11410@uc.msc.umn.edu>
Reply-To: dls@mace.cc.purdue.edu.UUCP (David L Stevens)
Organization: PUCC UNIX Group
Lines: 14


	Differing subnet sizes are not really a problem on all systems--
the "only if your software isn't up to snuff" comment applies.
	4.3BSD includes enhancements to ICMP to ask for the interface's
netmask ("ICMP_MASKREQ"). I don't know of any user-level program that uses
this (yet).
	Also, I don't think it's been clear that the "variable size" subnets
are by individual bits, not just bytes. You can split a class B net number
into 17 bits of network and 15 bits of host, if that's what you really want
to do. Some software only supports A subnetted to B and B subnetted to C
(ie, by bytes), though. Void where prohibited. Your mileage may vary.
	Of course, if you have sources, you can fix it.
-- 
					+-DLS  (dls@s.cc.purdue.edu)