From owner-freebsd-stable Fri Dec 20 13:59:10 2002 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4530C37B401 for ; Fri, 20 Dec 2002 13:59:09 -0800 (PST) Received: from smnolde.com (c-24-98-61-182.atl.client2.attbi.com [24.98.61.182]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8572643EE8 for ; Fri, 20 Dec 2002 13:59:08 -0800 (PST) (envelope-from scott@smnolde.com) Received: from [192.168.10.7] (helo=bsd.smnolde.com) by smnolde.com with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 3.36 #1) id 18PVAh-000FXo-00; Fri, 20 Dec 2002 16:59:07 -0500 Received: from scott by bsd.smnolde.com with local (Exim 3.36 #1) id 18PVAh-000HsY-00; Fri, 20 Dec 2002 16:59:07 -0500 Date: Fri, 20 Dec 2002 16:59:07 -0500 From: "Scott M. Nolde" To: redjupiter Cc: David Wolfskill , freebsd-stable@FreeBSD.ORG Subject: Re: fxp0 device - Intel NIC Message-ID: <20021220215907.GE67177@smnolde.com> References: <200212201615.gBKGF7IB016865@bunrab.catwhisker.org> <3E039092.2030609@ntlworld.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3E039092.2030609@ntlworld.com> User-Agent: Mutt/1.4i X-GPG_Fingerprint: 0BD6 DDB4 2978 EB60 E0C8 33F2 BC34 9087 D869 AB48 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG redjupiter(redjupiter@ntlworld.com)@2002.12.20 21:50:10 +0000: > HI Again, > > Sorry, was dragged out to continue christmas shopping by the wife :-) > > OK, I guess I can do that. My understanding was that each NIC has its > own unique MAC address and not two cards may have the same address. so > what you are saying now is that it's ok as long as they are on different > networks. I never understood it that way. > > I also understood that the MAC address is hard wired, i.e builtin in the > card. I know I sound confused, I don't just want to do it but I want to > understand it as well. I know some cards on soem embedded systems > have/must have the last three digits to be unique and so the programmer > is allowed to assign his own first three digits. > > Sorry to dwell on this but I really want to understand it. > > thanks. The MAC address must be unique to the network, as mentioned before, as the MAC address on a packet is only good until the next router, when it's changed for the next hop. You are correct in that the MAC is hardcoded, but that does not mean that you can't override it in software (which is what is suggested). More technical info can be found in any book explaining how TCP/IP works. Go ahead and try it... change the MAC to that of the realtek with the /etc/start_if.fxp0 file and see how it works. -- Scott Nolde GPG Key 0xD869AB48 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message