Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!csn!boulder!daemon
From: woods@ncar.UCAR.EDU (Greg Woods)
Newsgroups: comp.dcom.sys.cisco
Subject: multiple nets on one interface
Message-ID: <33413@boulder.Colorado.EDU>
Date: 19 Mar 91 08:27:51 GMT
Sender: news@boulder.Colorado.EDU
Lines: 15


> IP devices on different subnets on the same interface will
> use the cisco to talk to one another even though they
> are on the same physical cable.

  Not necessarily. We just run a default route to the router interface,
and a class B netmask, and depend on proxy arp to get packets to things
on different interfaces of the router (i.e. other subnets not on this
same cable). It works for us. Since the netmask is class B, different
net numbers on the same interface just speak directly to each other
without going through the router. The router is smart enough to know which
subnets it needs to proxy arp for on each interface (i.e. every subnet
EXCEPT the ones on this interface, it will proxy arp for on this interface).

--Greg