Xref: utzoo comp.protocols.appletalk:4906 comp.sys.mac.misc:6588
Newsgroups: comp.protocols.appletalk,comp.sys.mac.misc
Path: utzoo!utgpu!cunews!bnrgate!bwdls61.bnr.ca!bnr.ca!bschmidt
From: bschmidt@bnr.ca (Ben Schmidt)
Subject: Re: Macs on Ethernet
Message-ID: <1990Dec10.142536.7183@bwdls61.bnr.ca>
Sender: usenet@bwdls61.bnr.ca (Use Net)
Organization: Bell-Northern Research
References: <2415@sparko.gwu.edu>
Date: Mon, 10 Dec 90 14:25:36 GMT

In article <2415@sparko.gwu.edu> fc156111@seas.gwu.edu (Timothy A. Waire 
Jr.) writes:
> Do Macs connected to Ethernet have a physical address (not the number 
that
> AppleTalk assigns at StartUp) associated with them 

Yes.  For example, Apple's Ethernet card manufactured by 3COM, each have a 
unique 12 hex digit physical Ethernet address beginning with 3COM's vendor 
code of 02608C (from memory, I think).

> that can be monitored by  and IBM running on Ethernet???  
> 
> We are running EtherTalk 2.0.  The IBMS are connected to Novell Servers.

Well every 802.3 ethernet packet (e.g. EtherTalk 2.0) packet from the Mac 
will start out with its source Ethernet address set to the Mac's.  If the IBM and the Mac can see each other at the Link layer (e.g. no routers between them), the packets that reach the IBM will still have the Mac's Ethernet source address.  (If they do pass through a router, or a PC emulating a router, the Mac packet reaching your IBM will have the IBM-side-of-the-router's Ethernet address as it's source Ethernet address.)  From there, it's up to the software running on the IBM, as to whether these Ethern




et addresses are monitored.

Ben Schmidt     Bell-Northern Research, Ltd.   Ph: (613) 763-3906
Information     P.O. Box 3511, Station C       FAX:(613) 763-3283
Technology      Ottawa Canada K1Y 4H7          bschmidt@bnr.ca