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From: gah@hood.hood.caltech.edu (Glen Herrmannsfeldt)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: all of the ethernets interfaces with the same address!?
Message-ID: <gah.670631839@hoodlum>
Date: 2 Apr 91 22:37:19 GMT
References: <910329223628@wraith.netops.contel.com>
Sender: news@nntp-server.caltech.edu
Organization: California Institute of Technology, Pasadena
Lines: 15

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.  

I believe this is TCP/IP standard, though I can't find the
reference.  

This is interesting, though, because I once put two ports
of one machine, with different IP addresses on the same
net.  It seemed to work fine.

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