Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!ut-sally!husc6!rutgers!ucla-cs!zen!ucbvax!ISI.EDU!braden From: braden@ISI.EDU Newsgroups: comp.protocols.tcp-ip Subject: Re: How do you break up a B class number? Message-ID: <8707271647.AA00575@braden.isi.edu> Date: Mon, 27-Jul-87 12:47:59 EDT Article-I.D.: braden.8707271647.AA00575 Posted: Mon Jul 27 12:47:59 1987 Date-Received: Tue, 28-Jul-87 04:49:02 EDT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: The ARPA Internet Lines: 18 I'd like to understand the reason that you feel the need to split a class B network into different-sized subnets. What happens if you stick to a single subnet size? Although some of the comments in reply to your message have been somewhat overblown, the fact is that the technical mechanism to handle different-sized subnets of the same network is not generally available today. It may require carrying a 32-bit subnet mask along with each IP (sub-)network address in whatever IGP is used within the subnetted network. The only current IGP which does carry such a mask is Dave Mills' Hello protocol used in the Fuzzballs; however, you could probably hack the BSD routing table and daemon to do so. If you are not in a position to roll your own IGP in this fashion, you had better stick to a single subnet mask. Bob Braden