I thought about this a little bit...
With the normal IP software on most machines, you can't have two
interfaces in the same subnet, it's "illegal." You can contact it on either
interface, but it will either have to pick one to reply over for everything, or
get confused and not reply at all.
Here's my thought:
Other machines will know which interface they connect to, because presumably
they pick on of the two addresses, or they are using a different name or some
such. Other machines don't know it's the same machine. How about if the
the two interfaces keeps track of which interface the ARP came into, and stores
info in the ARP table along with the IP and MAC. Then, it would look in the
to figure out which interface (and hence, which address) to send it's packet
Only works for machines on the same subnet, though. Still has to have a
interface for off-subnet stuff.
---------- Previous Message ----------
From: rbrackett @ dsm.net (Richard Brackett) @ smtp
Date: 02/20/97 08:41:39 AM
Subject: Re: How to configure two network interface into a same subnet?
I don't believe that you are going to be able to make that configuration work.
How is TCP/IP supposed to choose
which adapter to use when talking to that subnet? Any multi-adapter
configuration I've seen or implemented needed
two different subnets to work. I've done this under various unix flavors,
Netware, and NT. Most OS's will allow
multiple same-subnet addresses to a single card, but not two different cards.
Others may have different experiences and I'd be interested in hearing from
anyone with more depth of knowledge
on the subject.
>>> Ruben Sajnovetzky <ruben @
ar> 02/19/97 11:59am >>>
+ I wants to configure the two ATM interfaces using same a subnet
+ address(18.104.22.168) on a SGI workstation, for example, one is
+ and another is 22.214.171.124. But I found if I assigned the two ATM interfaces
+ into same a subnet, the IRIX system couldn't work correctly. If I assiged the
+ two ATM interfaces into two different subnet(ex: 126.96.36.199 and
+ 188.8.131.52), our IRIX system could work correctly. Do you know that two
+ network interfaces(such as ATM, ethernet or FDDI) in a UNIX machine can be
+ assigned into same a subnet? If can, how should I configure?
I had same problem with Solaris 2.5, if someone knows the solution please let
Ruben Sajnovetzky - ruben @