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From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: How do you get a ENet Addr?
Message-ID: <65311@sgi.sgi.com>
Date: 27 Jul 90 10:54:59 GMT
References: <488@eng3.UUCP> <1990Jul25.090203.1@rogue.llnl.gov> <1990Jul25.184017.192@tandem.com>
Sender: rpw3@rigden.wpd.sgi.com
Reply-To: rpw3@sgi.com (Rob Warnock)
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Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 40

In article <1990Jul25.184017.192@tandem.com> kevinr@Tandem.COM writes:
+---------------
| In products we build, we give the board a default globally admin'ed 
| address.  We still allow the end user to change the current address,
| but the software will never let him pick a globally assigned
| style address.
+---------------

Notice that if are are running the Xerox NS (XNS) protocols on a multi-homed
host or gateway, you need to be able to set the physical address of all
Ethernet interfaces in the host to the same value, as XNS uses that address
as the host address. That is, in XNS the globally-unique "host address"
is a property of the *host*, not of the interface(s) as in TCP/IP.

[Reference: "Internet Transport Protocols", Xerox System Integration
Standard XSIS-028112, page 16]

What is often to simplify assignment of the "host address" is to use the
physical (globally administered) address off the "primary" network interface,
or if there is no reasonable notion of "primary", all the physical addresses
are read at boot time and the smallest/largest/one_in_slot#0/etc. is chosen
as "the" host address, and then that value is written back into *all* of the
network interfaces.

Clearly, your software restriction would prevent this.

+---------------
| Unfortunately, that part of the S/W hasn't been popular with our customers.
+---------------

I wonder why...   ;-}


-Rob

-----
Rob Warnock, MS-9U/510		rpw3@sgi.com		rpw3@pei.com
Silicon Graphics, Inc.		(415)335-1673		Protocol Engines, Inc.
2011 N. Shoreline Blvd.
Mountain View, CA  94039-7311