Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!ucbcad!pasteur!ucbvax!SUN.COM!nowicki
From: nowicki@SUN.COM (Bill Nowicki)
Newsgroups: comp.protocols.tcp-ip
Subject: Subnet support in SunOS 3.3
Message-ID: <8801182146.AA03342@speed.sun.com>
Date: 18 Jan 88 21:46:27 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 25

Last week there were several incorrect messages to this list about the
IP subnet support in SunOS releases.  As developer of this software, I
would like to brave the flames and clear up the misconceptions.

All SunOS releases support any number of any combination of Class A, B,
or C internet addreses, and will route between them.  Release 3.3 and
beyond (3.5 is the current release) support any number of non-subnetted
networks (standard subnet masks), and any number of interfaces on a
subnetted IP network (a single non-standard mask).  3.3 was to support
sites like Berkeley and Stanford, that tend to have a single class A or
B network number, with routers connecting the various subnets together,
and connecting them to the outside world (e.g. Arpanet).  Suns can be
used for any of these routing functions. Some more esoteric
configurations with multiple (DIFFERENT) non-standard netmasks on the
same machine are supported in a release that is currently in Beta
test.  ALL releases since 3.3 handled (and never forwarded) all six
kinds of broadcast addresses.  As described in RFC950, subnets of all
zeros should not be used, and a single netmask should be used throughout
a single IP network number.

Some specific examples of supported configurations are given in the
release documentation; in general it is a good idea to read the manual
first before posting a message to a world-wide distribution list.

	-- Bill Nowicki
	   Sun Microsystems