From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: LibIPQ issue Date: Wed, 09 Mar 2005 00:29:28 +0100 Message-ID: <422E3558.8050200@trash.net> References: <422C52AB.4030801@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Cc: netfilter-devel@lists.netfilter.org To: =?ISO-8859-1?Q?S=E9rgio_Bernardino?= In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org Sérgio Bernardino wrote: > After a bit more time working with this i realized something "interesting": > When i send a packet from a machine A to a machine B and capture it in > PRE_ROUTING, if i change the destination address so that it points to > machine C, the packet disappears and i can't track it anywhere. On the > other hand, if i instead change the source address of the packet so > that it points to machine C everything works fine. I can "see" the > packet traversing into machine B, which receives the packet and > promptly replies sending a packet to machine C. Machine A never > receives a reply to the packet it sent and machine C receives a reply > from a packet it never sent. Exactly the behaviour expected when > changing the source address field. Now, if this works in this case, > merely changing it to alter the destination address (my original > intention) should work also, but it doesn't. > My code can't be incorrect in a situation like this, so what exactly > is wrong? And is there a away to solve such situation? > Ideas anyone? Have you got IP forwarding enabled ? echo 1 >/proc/sys/net/ipv4/ip_forward Regards Patrick