From owner-freebsd-questions@FreeBSD.ORG Tue Nov 6 22:41:44 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 21D3216A418 for ; Tue, 6 Nov 2007 22:41:44 +0000 (UTC) (envelope-from malcolm.clarke@brunel.ac.uk) Received: from astro.systems.pipex.net (astro.systems.pipex.net [62.241.163.6]) by mx1.freebsd.org (Postfix) with ESMTP id E0A4D13C4B2 for ; Tue, 6 Nov 2007 22:41:43 +0000 (UTC) (envelope-from malcolm.clarke@brunel.ac.uk) Received: from [192.168.0.101] (81-86-251-96.dsl.pipex.com [81.86.251.96]) by astro.systems.pipex.net (Postfix) with ESMTP id 79737E0009B1 for ; Tue, 6 Nov 2007 22:10:58 +0000 (GMT) Message-ID: <4730E659.4020303@brunel.ac.uk> Date: Tue, 06 Nov 2007 22:10:33 +0000 From: Malcolm Clarke User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: IPFW and ICMP with timestamp option X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 06 Nov 2007 22:41:44 -0000 I have configured a machine with 2 NIC and IPFW in a rather simplistic way as we are using it to emulate different link characteristics rather than as an actual firewall. 00100 4 355 pipe 1 ip from any to any via de0 in 00200 1 56 pipe 2 ip from any to any via de0 out 00300 0 0 pipe 3 ip from any to any via de1 in 00400 3 288 pipe 4 ip from any to any via de1 out 65535 4 246 deny ip from any to any The configuration works fine and traffic crosses the firewall without problem, except ICMP packets having timestamp or routing option, and these are not returned. Is there a way to allow these packets to enter/exit the firewall? Regards Malcolm -- --------------------------------------------------- Dr Malcolm Clarke Senior Lecturer in Data Communication Systems and Telemedicine Department of Information Systems and Computing Brunel University Uxbridge Middlesex UB8 3PH UK Tel: +44 1895 265053 Fax: +44 1895 251686 http://www.brunel.ac.uk/about/acad/siscm/research/themes/is/groups/bright/people ----------------------------------------------------