From owner-freebsd-hackers Tue Jan 2 21: 1:17 2001 From owner-freebsd-hackers@FreeBSD.ORG Tue Jan 2 21:01:15 2001 Return-Path: <owner-freebsd-hackers@FreeBSD.ORG> Delivered-To: freebsd-hackers@freebsd.org Received: from tsunami.waterspout.com (tsunami.waterspout.com [208.13.56.11]) by hub.freebsd.org (Postfix) with ESMTP id 23A5937B400 for <freebsd-hackers@freebsd.org>; Tue, 2 Jan 2001 21:01:15 -0800 (PST) Received: from dustdevil.waterspout.com (tsunami.fw.waterspout.com [208.13.60.34]) by tsunami.waterspout.com (8.9.3/8.9.3) with ESMTP id AAA66836 for <freebsd-hackers@freebsd.org>; Wed, 3 Jan 2001 00:01:13 -0500 (EST) (envelope-from csg@dustdevil.waterspout.com) Received: (from csg@localhost) by dustdevil.waterspout.com (8.11.1/8.11.1) id f0355Ae16857; Wed, 3 Jan 2001 00:05:10 -0500 (EST) (envelope-from csg) Date: Wed, 3 Jan 2001 00:04:58 -0500 From: "C. Stephen Gunn" <csg@waterspout.com> To: Doug White <dwhite@resnet.uoregon.edu> Cc: freebsd-hackers@freebsd.org Subject: Re: ARP question. Message-ID: <20010103000458.A16838@waterspout.com> References: <5.0.2.1.0.20010102023010.00a101f0@pop6.sympatico.ca> <Pine.BSF.4.21.0101021400490.38463-100000@resnet.uoregon.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <Pine.BSF.4.21.0101021400490.38463-100000@resnet.uoregon.edu>; from dwhite@resnet.uoregon.edu on Tue, Jan 02, 2001 at 02:02:03PM -0800 Sender: csg@dustdevil.waterspout.com Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Jan 02, 2001 at 02:02:03PM -0800, Doug White wrote: > > arp: 200.42.126.18 moved from 00:e0:7d:7b:53:f0 to 00:c0:df:f4:ac:05 on ed0 > > From personal experience, Linux has this nasty bad habit of broadcasting > ARPs on all interfaces. For this reason multihomed Linux boxes should be > banned. > > We got tired of it at my previous job and patched around it on the linux > machine. I've seen similar things from Linux. In my experience it was an ARP who-has request with the source IP of the other interface. Linux apparently doesn't learn ARP addresses this way, but FreeBSD takes note, which causes the problem mentioned above. Is the Linux box a firewall/NAT box of some kind? Having two interfaces on the same wire can be a problem. FreeBSD's ARP implementation gets rather upset about seeing the packets twice, since the receive interface is significant. Broadcast protocols aren't guaranteed to be idempotent. Your mileage may vary. - Steve -- C. Stephen Gunn URL: http://www.waterspout.com/ WaterSpout Communications, Inc. Email: csg@waterspout.com 427 North 6th Street Phone: +1 765.742.6628 Lafayette, IN 47901 Fax: +1 765.742.0646 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message