Henrik Thanks for your answer. If I understand correct, if the local endpoint of the socket is not bound, then: 1. The routing decision is taken, and the source IP address is assigned to the IP address of the interface through which the packet would leave the firewall. 2. The packet travels through the OUTPUT chain and does not pass the routing decision anymore, because the routing decision was already taken before going to the OUTPUT chain. Is there any specific reason why the packet doesn't pass the routing decision the second time? Regards Wim Henrik Nordstrom wrote: >On Mon, 15 Sep 2003, Wim Ceulemans wrote: > > > >>In paragraph 6.2 of the iptables-tutorial the following is said: >>"The OUTPUT chain is used for altering locally generated packets (i.e., >>on the firewall) before they get to the routing decision. >> >> > >Yes. > > > >>But in paragraph 3.1, the "Traversing of tables and chains" diagram, we >>see the "Routing decision" is listed after the "Local process" and >>BEFORE! the packet goes to the output chain. >> >>So which one is right? Does the routing decision take place after or >>before the packet travels through the output chain? >> >> > >Both, depending on the situation. > >if the local endpoint of the socket sending the packet is bound then >routing occurs after OUTPUT. > >If the local endpoint of the socket is NOT bound then routing occurs >before OUTPUT to assign the source address. > >Regards >Henrik > > > > -- Wim Ceulemans R&D Engineer Secure Internet Communication with aXs Guard Able NV Leuvensesteenweg 282 - B-3190 Boortmeerbeek - Belgium Phone: + 32 15 50.44.00 - Fax: + 32 15 50.44.09 E-mail: wim.ceulemans@able.be -- Security check on this e-mail has been done by aXs GUARD (http://www.axsguard.com)