From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Clark Subject: Re: clone packet with new destination address Date: Fri, 22 Oct 2010 10:16:14 -0400 Message-ID: <4CC19CAE.1030306@earthlink.net> References: <4CC1843F.8050903@earthlink.net> Reply-To: sclark46@earthlink.net Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netfilter-devel@vger.kernel.org To: Changli Gao Return-path: Received: from elasmtp-banded.atl.sa.earthlink.net ([209.86.89.70]:43141 "EHLO elasmtp-banded.atl.sa.earthlink.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278Ab0JVOQT (ORCPT ); Fri, 22 Oct 2010 10:16:19 -0400 In-Reply-To: Sender: netfilter-devel-owner@vger.kernel.org List-ID: On 10/22/2010 09:36 AM, Changli Gao wrote: > On Fri, Oct 22, 2010 at 9:24 PM, Changli Gao wrote: > >> On Fri, Oct 22, 2010 at 8:31 PM, Stephen Clark wrote: >> >>> Hello, >>> >>> Problem: >>> I have a two monitoring servers behind a a linux firewall, one is primary >>> and one is backup. >>> In the field we have units sending udp informational packet to the primary >>> server. On the >>> linux firewall I would like to copy this packet and change the destination >>> address of the copied >>> packet to point to the backup server. Is there a way to do this without >>> writing any code? >>> >>> NOTE: >>> Currently the firewall is FreeBSD and we accomplish this rather easily using >>> ipfw along with natd, but we want to move to linux for our firewall. >>> >>> >> I think you can use tc action mirred to mirror the packets to a fake >> NIC device ifb, and use tc action nat to dnat the packets received >> from ifb. >> >> > Oh, iptables can also do it. Please see iptables target TEE and RAWNAT > in xtables-addons. http://xtables-addons.sourceforge.net/ > > Not to seem dumb - but I tried xtables TEE without any success. Could you provide a detailed example? Thanks, Steve -- "They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." (Ben Franklin) "The course of history shows that as a government grows, liberty decreases." (Thomas Jefferson)