From owner-freebsd-questions@FreeBSD.ORG Thu Feb 5 12:05:23 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 4402B16A4CE for ; Thu, 5 Feb 2004 12:05:23 -0800 (PST) Received: from home.mnet.bg (home.mnet.bg [193.110.223.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1D1F643D6E for ; Thu, 5 Feb 2004 12:05:19 -0800 (PST) (envelope-from dpenev@mnet.bg) Received: from localhost (home [127.0.0.1]) by home.mnet.bg (Postfix) with ESMTP id D70743B354; Thu, 5 Feb 2004 22:03:51 +0200 (EET) Received: from venus.dpsca.bg (ip220-81.mnet.bg [193.110.220.81]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by home.mnet.bg (Postfix) with ESMTP id 1F3963B2FF; Thu, 5 Feb 2004 22:03:51 +0200 (EET) Received: from earth.dpsca.bg (earth.dpsca.bg [192.168.1.1]) by venus.dpsca.bg (8.12.9/8.12.9) with ESMTP id i15K44rI031927; Thu, 5 Feb 2004 22:04:04 +0200 (EET) Received: (from dpenev@localhost) by earth.dpsca.bg (8.12.10/8.12.10/Submit) id i15K6o2b001533; Thu, 5 Feb 2004 22:06:50 +0200 (EET) (envelope-from dpenev) Date: Thu, 5 Feb 2004 22:06:50 +0200 From: Dancho Penev To: Alexander Botov Message-ID: <20040205200650.GD630@earth.dpsca.bg> Mail-Followup-To: Alexander Botov , freebsd-questions@FreeBSD.ORG References: <004f01c3ebea$5974d750$0200a8c0@ALIENX> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <004f01c3ebea$5974d750$0200a8c0@ALIENX> User-Agent: Mutt/1.4.1i X-Virus-Scanned: by amavisd-new-20030616-p7 (Debian GNU/Linux) at mnet.bg 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 20:05:23 -0000 On Thu, Feb 05, 2004 at 03:17:04PM +0200, Alexander Botov wrote: >From: "Alexander Botov" >To: >Date: Thu, 5 Feb 2004 15:17:04 +0200 >Subject: forwarding with ttl=1 > >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 ? You don't need to hack the kernel because this was already did. Add options IPSTEALTH in your kernel configuration file, build the new kernel and set net.inet.ip.ipstealt sysctl variable to 1. For more information see /usr/src/sys/conf/NOTES and /usr/src/sys/netinet/ip_input.c. > >please excuse my English >_______________________________________________ >freebsd-questions@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-questions >To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" -- Dancho Penev