From owner-freebsd-questions@FreeBSD.ORG Thu Apr 29 12:29:39 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CC86016A4D4 for ; Thu, 29 Apr 2004 12:29:39 -0700 (PDT) Received: from natsmtp00.rzone.de (natsmtp00.rzone.de [81.169.145.165]) by mx1.FreeBSD.org (Postfix) with ESMTP id 14A3343D54 for ; Thu, 29 Apr 2004 12:29:39 -0700 (PDT) (envelope-from andrea@ae4u.de) Received: from ae4u.de (mail.engel-kg.com [62.80.41.218]) by post.webmailer.de (8.12.10/8.12.10) with ESMTP id i3TJTbbo021105 for ; Thu, 29 Apr 2004 21:29:37 +0200 (MEST) Message-ID: <4091740F.7000908@ae4u.de> Date: Thu, 29 Apr 2004 21:30:55 +0000 From: "Andrea E." Organization: http://www.ae4u.de/ User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.5b) Gecko/20030903 X-Accept-Language: de-de, en-us, en MIME-Version: 1.0 To: freebsd-questions@FreeBSD.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: ipfw with NAT and ARP X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Apr 2004 19:29:40 -0000 Hi, I am a newbie and my question is very easy perhaps. I work with FreeBSD 5.2.1 I would like to configure a firewall with to interfaces (xl0 = LAN, xl1 = External) For NAT I have configured like discribed in the manualpage of natd: ipfw -f flush ipfw add divert natd all from any to any via xl1 ipfw add allow all from any to any -> all is fine. But, I wont so a simple firewall and for this reason, first I want to configure the ICMP-protocol: ip_ext => External IP-Address ipfw -f flush ipfw add divert natd all from any to any via xl1 ipfw add allow icmp from $ip_ext to any icmptypes 8 out via xl1 ipfw add allow icmp from any to $ip_ext icmptypes 0 in via xl1 -> It's not ok. With "ethereal" no pakets are going out (test from an other system, connected with a HUP.) When testing "ping" from external to external IP-Adress of my firewall, the ARP-request: to broadcast Who has xxx.xxx.xxx.xxx? Tell xxx.xxx.xxx.xxx fails -> seems to have a problem to let ARP through the firewall. Above -> "ipfw add allow all from any to any" let ARP through the firewall. So I think, thats the configuration of the rest of my computer (like kernel, rc.conf, etc. ist ok) And there are no ARP-protocol in /etc/protocols, so I don't know, what I can do now. There is a bug: After restarting system with above configuration of icmp-protocol no ping-request is going out. After a flush of all rules and configuring of "ipfw add allow all from any to any" ping-request get an answer. Very interesting is to flush all rules und to configure the firewall like the first configuring (to allow special rules for icmp-protocol -> all works very fine. ping-request get an answer. Whenn restarting system the ping-request get no answer again, I mean, the ping-request is not send out. Can anybody help me? Hope to get an answer. I hope you can understand me, my English isn't very well. Greatings from Berlin, Andrea E.