Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!wang!fitz
From: fitz@wang.com (Tom Fitzgerald)
Newsgroups: comp.protocols.tcp-ip
Subject: Many logical nets on a single physical net
Message-ID: <1990Feb23.214634.8645@wang.com>
Date: 23 Feb 90 21:46:34 GMT
Organization: Wang Labs, Lowell MA, USA
Lines: 28

Is it possible to have a single Ethernet with multiple IP network addresses
on it, and get the separate IP nets talking to each other?  Especially, is
it possible to do this cheaply?

We've got a number of separate Ethernets, with separate IP addresses, that
we want to connect together.  In the long run, as traffic rises (and
equipment becomes available) we'll be putting in proper gateways where
they look necessary.  But we want to get the machines on the various nets
talking to each other ASAP.

We don't want to renumber all the IP addresses, since we'd just have to
change them back when we started isolating the various nets with gateways.
And it may be some time before we can get all the gateways in place.

The ideal solution from our point of view would be a "gateway" with a single
interface and many IP addresses for it.  It would accept all inter-net
packets from all logical nets, and send them back out again, as-is, on the
same wire, to the right final destination.  Are there any gateways or
routers that are capable of this?  All the ones I have specs on assume that
interfaces map one-to-one with logical nets.

If there aren't any machines like this, what's the least we could do to get
this working?  Any and all info appreciated.

---
Tom Fitzgerald   fitz@wang.com
Wang Labs        ...!uunet!wang!fitz
Lowell MA, USA   1-508-967-5278