Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!hellgate.utah.edu!csn!boulder!daemon
From: William "Chops" Westfield <BILLW@mathom.cisco.com>
Newsgroups: comp.dcom.sys.cisco
Subject: Re: all of the ethernets interfaces with the same address!?
Message-ID: <33874@boulder.Colorado.EDU>
Date: 3 Apr 91 11:29:58 GMT
Sender: daemon@boulder.Colorado.EDU
Lines: 23


    In all TCP/IP implementations I know of, all ports on the
    same machine use the same ethernet (hardware) address.  On
    initialization, it reads the ROM on the first port it finds,
    and stores this in all the ports.  

No, this is incorrect.  In fact, I don't know of ANY TCP implementations
that do this, although it is common in come other protocols (eg XNS).
In particular, unless you are running some other protocols, cisco routers
will leave the ethernet address of each ethernet interface at its original
(and unique) value.


    I think cisco routers know how to put more than one IP
    address per port, anyway.   At least that is what I
    was told.

This is true.  I can't think of any reason to connect more than one
ethernet interface in a router to the same cable segment.

Bill Westfield
cisco Systems.
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