Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!bu-cs!purdue!decwrl!hplabs!ucbvax!UC.MSC.UMN.EDU!slevy
From: slevy@UC.MSC.UMN.EDU ("Stuart Levy")
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  HYROUTE(TCP/IP gateway between HYPERchannel and ethernet)
Message-ID: <8805211533.AA21218@uc.msc.umn.edu>
Date: 21 May 88 15:33:57 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 23

If you don't use hyroute, then the hyperchannel driver will demand
an IP address of the form

	<anything>.<loopback_code>.<adapter_address>.<port_number>

(with each <xxx> an 8-bit field) and then you really do need a class A net.

But if you use hyroute, you can just put "direct" statements into
/etc/hyroute.conf and create an arbitrary mapping of
IP addresses to (loopback_code, adapter_addr, port_number, other_bits) tuples.

In other words, you can use any IP addresses you wish -- they should
fit just fine into a subnetted class B network.

Since Crays don't do subnetting yet (in 3.0 at least, I think not in 4.0
either) you may have to use another machine as a subnet gateway, but that
shouldn't be too troublesome.

I know the above is true for the Cray-2 since we're actually using
hyroute in this way.  I'm reasonably certain that X-MP's act the same way.

	Stuart Levy, Minnesota Supercomputer Center
	slevy@uc.msc.umn.edu, (612) 626-0211