From owner-freebsd-questions@FreeBSD.ORG Thu Feb 5 10:01:46 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 E064316A532 for ; Thu, 5 Feb 2004 10:01:46 -0800 (PST) Received: from mailhost.cotse.com (mailhost.cotse.com [216.112.42.58]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8C86343D48 for ; Thu, 5 Feb 2004 10:01:40 -0800 (PST) (envelope-from freebsd@jyroscop.cotse.net) Received: from www.cotse.net (www [216.112.42.60]) by mailhost.cotse.com (5.7.4/5.7.4) with ESMTP id i15I1bp3004417; Thu, 5 Feb 2004 13:01:37 -0500 (EST) (envelope-from freebsd@jyroscop.cotse.net) Received: (from nobody@localhost) by www.cotse.net (5.7.4/5.7.4) id i15I1bKc023060; Thu, 5 Feb 2004 13:01:37 -0500 (EST) Received: from 127.0.0.1 by www.cotse.net with HTTP; Thu, 5 Feb 2004 13:01:37 -0500 (EST) Message-ID: In-Reply-To: <004f01c3ebea$5974d750$0200a8c0@ALIENX> References: <004f01c3ebea$5974d750$0200a8c0@ALIENX> Date: Thu, 5 Feb 2004 13:01:37 -0500 (EST) From: "Stephen L Martin" To: alexb@mail.bg X-Abuse-To: abuse@dissimulo.com MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 Importance: Normal cc: freebsd-questions@freebsd.org Subject: Re: forwarding with ttl=1 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, 05 Feb 2004 18:01:47 -0000 Alex, When posting please wrap your lines...they are easier to read and some MUA's don't deal well with them...including mine :) Thanks. This situation is kind of funny, I've never heard of an ISP doing this. I belive what you want to do is, if you are using IpFilter, use the fastroute keyword. You can find more about it at the link[1] posted below. Just do a search on the page for fastroute. There are probably options for the alternate packet filters (ipfw, pf) also. Just read the howto corresponding to the packet filters name and you should find out some more information. [1]http://www.obfuscation.org/ipf/ipf-howto.txt --Stephen > Hi All > > I am newbie with configuring networks under FreeBSD . I have small network > with gateway running on FreeBSD 5.2 Release .My ISP offers me pppoe > service for connecting to Internet . I didn't have problems with > configuring ppp with pppoe . I used nat option wchich works fine for > masquerading the local network from the world . The problem is that the > ISP's gateway returns every time packets with ttl=1 which makes further > forwarding impossible . My gateway returns icmp error mesage "time > exceeded" and discards packets . I want to know if I made some mistake > with configuring nat service or if not what is the solution of the problem > ? Is there any service that can increment ttl and process the packet ? I > tried to avoid the checking of ttl in the ip_forward() function in > ip_input.c and skipping the decrement of ttl and everything works fine but > i think that this is very ugly kernel hack . Probably there is an easy and > elegant solution . Any ideas ? > > please excuse my English