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From: ted@blia.BLI.COM (Ted Marshall)
Newsgroups: comp.sys.dec
Subject: Re: Getting ETHERNET address of VAX adapter
Summary: Computing Ethernet address from DECnet address
Message-ID: <11288@blia.BLI.COM>
Date: 13 Apr 90 16:49:22 GMT
References: <3431.26246304@fps.mcw.edu> <10847@cbmvax.commodore.com>
Organization: Britton Lee, Los Gatos, CA
Lines: 20

In article <10847@cbmvax.commodore.com>, grr@cbmvax.commodore.com (George Robbins) writes:
> Note that this shows you the original hardware address, not whatever
> deviated thing DECnet sets it to (something based on the DECnet area.node).

The working Ethernet address is set from the DECnet address as follows:

Compute (Area * 1024) + Node_within_area, byte swap the result, producing
the low two bytes of the Ethernet address (The other four bytes are
AA-00-04-00).

For example, DECnet address 4.72 yields (4 * 1024) + 72 = 4168 = 0x1048.
Swap the bytes and insert into the Ethernet address, yielding
AA-00-04-00-48-01.

Hope this helps.

-- 
Ted Marshall          ...!ucbvax!mtxinu!blia!ted  <or>  ted@blia.bli.com
ShareBase Corp., 14600 Winchester Blvd, Los Gatos, Ca 95030     (408)378-7000
The opinions expressed above are those of the poster and not his employer.