From owner-freebsd-hackers Tue May 18 1:13: 3 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from imr1.srv.uk.deuba.com (imr1.srv.uk.deuba.com [194.196.205.49]) by hub.freebsd.org (Postfix) with ESMTP id BCD3814E59 for ; Tue, 18 May 1999 01:12:59 -0700 (PDT) (envelope-from Steve.Gailey@db.com) Received: from bmr2-e1.srv.uk.deuba.com by imr1.srv.uk.deuba.com id JAA04328; Tue, 18 May 1999 09:12:58 +0100 (BST) Received: from pow.srv.uk.deuba.com by bmr2-e1.srv.uk.deuba.com id JAA18810; Tue, 18 May 1999 09:12:57 +0100 (BST) Received: from dmglon010020773 by pow.srv.uk.deuba.com id JAA08915; Tue, 18 May 1999 09:12:57 +0100 (BST) Message-Id: <199905180812.JAA08915@pow.srv.uk.deuba.com> From: "Steve Gailey" To: hackers@freebsd.org Date: Tue, 18 May 1999 09:09:37 +0100 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: ifconfig: changing mac address Reply-To: Steve.Gailey@db.com References: <199905141729.LAA11747@mt.sri.com> In-reply-to: X-mailer: Pegasus Mail for Win32 (v3.11) Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG My experience is that most modern (and many older) PC NIC's are able to change their MAC address. The question really is, how should I do this from within FreeBSD. Is there a standard entry into the drivers to do this? If you are wondering why I want to do this, I am looking at hot standby and redundant takeover stuff for high availability systems. Steve > On Fri, 14 May 1999, Nate Williams wrote: > > > I know it's possible to bridge ethernet segments under linux, and the > > > only way that bridging can be implemented is if the MAC address be > > > changed in software on a per-packet basis. > > > > What do you mean 'bridge ethernet segments'? > > A bridge will listen on two specific ethernet ports and decide which MAC > addresses are on which side of the bridge and only forward those packets > which need to cross the bridge. > > In addition, bridges use the IEEE spanning protocol to get rid of possible > loops when there are multiple bridges and switches connected together. An > ethernet switch is in essence a bridge with alot of ports. > > > > > > Very likely there are not kernel facilities to do this, but the > > > existence of bridging code convinces me that it must be possible to > > > alter mac address. > > > > Not that I'm aware of. Too many licensing schemes rely on mac addresses > > to provide the unique 'fingerprint' to have this be something that is > > easily doable. > > > > You're too stubborn here. If a linux box can bridge, then it logically > must be able to change MAC address on a per-packet basis. > > Also when a PC runs a DECNET client, it must also be able to change > ehternet addresses from the base value in the card. > > -- C. Mott > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message