From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: Date: Wed, 30 Mar 2005 15:00:57 +0200 From: To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Subject: Re: [9fans] unique MAC address allocation? In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit References: <7245e6c140059fc72e3b9bb976945343@collyer.net> Topicbox-Message-UUID: 2e4821c6-ead0-11e9-9d60-3106f5b1d025 On Wed, 30 Mar 2005 12:27:07 +0100, Charles Forsyth wrote: > >>Many cards, not just new ones, permit overriding the default MAC > >>address and the plan 9 drivers generally support this (with > >>ea=XXXXXXXXXXXX in the ether's plan9.ini entry). > > indeed most cards require the address to be read from somewhere else (eg, EEPROM) > and explicitly programmed into the device proper, so that being > able to override it is not unusual. I was probably not precise and the question was not well thought through. What I wanted to ask was: I did override the MAC address - for some obscure reason, I can't remember - some 12 years ago on DOS via the packet driver interface, but is it the OS's responsibility to detect and possibly deal with MAC address collision or would the Ethernet layer take care of it? Instead of googling for "MAC address" etc., I should have searched for "Ethernet standard", days ago. The pages I needed were http://standards.ieee.org/faqs/OUI.html and http://standards.ieee.org/getieee802/802.3.html . Now I only have to read thorugh the standard. Probably the subject is not worth it (~1500 pages?). The OS can take care of the problem, if the driver supports MAC address collision detection.