Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!sdd.hp.com!ucsd!ucbvax!TGV.COM!adelman
From: adelman@TGV.COM (Kenneth Adelman)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Multiple IP networks on one Ethernet interface
Message-ID: <900606160812.202000ad@TGV.COM>
Date: 6 Jun 90 23:15:30 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Adelman@TGV.COM (Kenneth Adelman)
Organization: The Internet
Lines: 34

> I know that the general philosophy in interconnecting IP networks is to use
> a router with two interfaces.  I would like a cheaper solution and was wondering
> if anyone has got this to work in practice:
>
> We have several organizations with TCP/IP networks, and we have a class B
> network number that we divided up into subnetworks (23 bit mask) and allocate
> subnetworks to the organizations.  Now the organizations want to talk to each
> other.  They are all on Ethernet networks.  I would like to know if any of
> the commercially-available TCP/IP packages have the capability of either:
>
>      1)  sending and receiving IP packets for more than one subnetwork
>	   over the same Ethernet interface.
>
>  or: 2)  routing packets between two or more subnetworks over the
>	   same Ethernet interface.

    Our MultiNet TCP/IP product for VMS can do this; it isn't
documented but customer service can give you the instructions for
enabling it.  We don't want to encourage people to run multiple
network numbers on the same cable because of the potential for
problems with broadcasts.

    Basically we allow you to create two `interfaces' for one ethernet
controller.  Each has its own address, and you can gateway between
them, run routing protocols, etc, just as if you had multiple
controllers on separate cables.  This would allow you to do with (1)
and (2) above.

    If you have any other questions, give me mail or a call at
800-TGV-3440 or 408-427-4366.  If you'd like to try it, we have an
evaluation/trade-in program so I can get a copy right out to you.

						    Kenneth Adelman
						    TGV, Inc.