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From: tsuchiya@THUMPER.BELLCORE.COM (Paul Tsuchiya)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  Subnetting Class B Internet Number
Message-ID: <9106212117.AA17458@chiya.bellcore.com>
Date: 21 Jun 91 21:17:37 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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You should read RFC 1219 about this.  It doesn't discuss
all the pros and cons of every possible method, but does
give one method that is the best known (I think) but requires
variable-mask routing protocols like OSPF.

PT