From mboxrd@z Thu Jan 1 00:00:00 1970 From: "James R. Leu" Subject: Re: IP stack question (how to force pkts to not route locally, but go out interfaces regardless of destination) Date: Wed, 28 Aug 2002 07:41:12 -0500 Sender: netdev-bounce@oss.sgi.com Message-ID: <20020828074112.A13868@nero.doit.wisc.edu> References: <3D6C6CF6.9040002@candelatech.com> Reply-To: jleu@mindspring.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Cc: jamal , "Bloch, Jack" , "'netdev@oss.sgi.com'" Return-path: To: Ben Greear In-Reply-To: <3D6C6CF6.9040002@candelatech.com>; from greearb@candelatech.com on Tue, Aug 27, 2002 at 11:25:58PM -0700 Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Hello, How about changing the preference of the 'local' table (kernel change required) and inserting a new table (via iptables) that had rules like "if src is local, and dest = 192.168.1.1 then send out eth0" Jim On Tue, Aug 27, 2002 at 11:25:58PM -0700, Ben Greear wrote: > > jamal wrote: > > Ben Wrote: > >>I would actually like to be able to force a machine to not do local > >>routing as well, and force packets out over an interface even if > >>the destination is a local IP, using source-based-routing, > >>or something similar. There is no way to do this currently? > >> > > > > > > Try that SO_DONTROUTE and see if solves your problem; you probably have to > > bind the socket to a specific device as well; > > For all that trouble, i would suggest you may just as well write a sock > > packet based app. > > I am back to trying to figure out how to make this work. I'm tried source > based routing, and it does not work (it routes internally). > > I read the help on SO_DONTROUTE, but it seems to make the kernel not able > to send to a router. I would like to be able to route, ie port a -> router -> port b > > I already bind to a particular port and IP, and use policy based routing > (source based routing) to make sure the packet is sent out the correct > local interface. > > I just need to find the routing logic that notices the destination IP is local > and tell it to quit looking (probably for a particular socket, as I can > see how this could break applications who didn't expect it) > > I dug through the code once before looking for this, and didn't find > what I needed. Can anyone suggest the right files and/or methods to > look in? > > Thanks, > Ben > > > > > cheers, > > jamal > > > > > -- > Ben Greear > President of Candela Technologies Inc http://www.candelatech.com > ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear > > -- James R. Leu