From owner-freebsd-net Fri Oct 9 04:12:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id EAA12476 for freebsd-net-outgoing; Fri, 9 Oct 1998 04:12:05 -0700 (PDT) (envelope-from owner-freebsd-net@FreeBSD.ORG) Received: from mail.ftf.dk (mail.ftf.net [129.142.64.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id EAA12444 for ; Fri, 9 Oct 1998 04:12:01 -0700 (PDT) (envelope-from regnauld@deepo.prosa.dk) Received: from mail.prosa.dk ([192.168.100.254]) by mail.ftf.dk (8.8.8/8.8.8/gw-ftf-1.0) with ESMTP id NAA26809 for ; Fri, 9 Oct 1998 13:17:03 +0200 (CEST) (envelope-from regnauld@deepo.prosa.dk) X-Authentication-Warning: mail.ftf.dk: Host [192.168.100.254] claimed to be mail.prosa.dk Received: from deepo.prosa.dk (deepo.prosa.dk [192.168.100.10]) by mail.prosa.dk (8.8.8/8.8.5/prosa-1.1) with ESMTP id NAA10747 for ; Fri, 9 Oct 1998 13:30:32 +0200 (CEST) Received: (from regnauld@localhost) by deepo.prosa.dk (8.8.8/8.8.5/prosa-1.1) id NAA10721; Fri, 9 Oct 1998 13:22:53 +0200 (CEST) Message-ID: <19981009132253.64247@deepo.prosa.dk> Date: Fri, 9 Oct 1998 13:22:53 +0200 From: Philippe Regnauld To: freebsd-net@FreeBSD.ORG Subject: MAC masquerading Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.88e X-Operating-System: FreeBSD 2.2.6-RELEASE i386 Phone: +45 3336 4148 Address: Ahlefeldtsgade 16, 1359 Copenhagen K, Denmark Organization: PROSA Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org [Can't find original message: the post I had forwarded from Bugtraq which contained a patch for linux-2.0.35 to do MAC masquerading] As Luigi mentioned, it was a performance killer, since it involved putting the card in promiscuous mode to snarf all the frames you'd "aliased" you NIC to grab. Someone answered on Bugtraq: -----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<----- Date: Thu, 8 Oct 1998 10:45:50 -0700 From: pedward@WEBCOM.COM Subject: Re: linux 2.0.35 ip aliasing with aliased hwaddr To: BUGTRAQ@NETSPACE.ORG The appropriate way to perform this is either: Set the new hwaddr in the card's filter list (most ethernet cards have a hardware packet filter, which filters ethernet frames based upon the hwaddr) Configure the card to do true MAC masquerading. This is possible on a number of cards, however I believe the list is more limited than the one above. Intel EEPro 10/100's will do MAC masquerading. -----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<----- Now, the reason I'm interested in this is to do make cheap "quick failover" systems, where a backup system, identical to the first, monitors the state of the primary at all times. When it fails for a given period, grab the MAC address, and act as the first. The reverse behavior would be expected of the first system (check for an existing ARP/MAC entry when coming up again, and already taken, take up a third MAC address, and so forth...) This is poor man's redundancy, but I have couple of servers acting as bastion hosts I'd like to do this with (using rsync, amonng other things...). -- -[ Philippe Regnauld / sysadmin / regnauld@deepo.prosa.dk / +55.4N +11.3E ]- The Internet is busy. Please try again later. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message