From owner-freebsd-security Tue Oct 16 23:58:37 2001 Delivered-To: freebsd-security@freebsd.org Received: from yorktown.francisscott.net (yorktown.francisscott.net [216.179.185.125]) by hub.freebsd.org (Postfix) with ESMTP id AD3E237B40D for ; Tue, 16 Oct 2001 23:58:23 -0700 (PDT) Received: from gatekeeper.heavymetal.org (cy565913-a.rdondo1.ca.home.com [24.177.248.173]) by yorktown.francisscott.net (8.11.6/8.11.6) with ESMTP id f9H6wB804364 for ; Tue, 16 Oct 2001 23:58:11 -0700 Received: from zeppelin (zeppelin.heavymetal.org [192.168.250.7]) by gatekeeper.heavymetal.org (8.11.6/8.11.6) with SMTP id f9H6wAX03567 for ; Tue, 16 Oct 2001 23:58:10 -0700 (PDT) (envelope-from scott@lampert.org) Message-ID: <000f01c156d9$152988a0$07faa8c0@zeppelin> From: "Scott Lampert" To: Subject: Bridging Firewall - 3 interfaces - arp issue Date: Tue, 16 Oct 2001 23:58:10 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org I have a box I've setup as a bridging firewall with ipfw. It has 3 interfaces - two are bridged, without IP addresses, and the third has an IP address and is connected to the inside network. Basically it looks like this: ************ * Internet * **+******** | 192.168.1.1/24 | | | bridge outside | +--+-------+ 192.168.1.2/24 | Firewall Box +-----+ +--+-------+ | | bridge inside | | | | +-+-------+ +-----------| Switch | +--------- + I hope the poor ascii art helps rather than hinders. :) In any event, I've noticed after running the firewall for a few hours that I start getting the following message in my dmesg output: arp: 00:aa:bb:cc:dd:ee is using my IP address 192.168.1.2! xx ouch, bdg_forward for local pkt The box is complaining about the third interface saying it has the IP its supposed to have. For some reason the box doesn't realize that its own interface is answering arps correctly. Is this normal behavior or have I misconfigured something? Do I need to add the third interface to the bridge configuration? -Scott To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message