Ok now I see the problem. The same external source ip can send to the same internal DMZ IP ... correct ? [Appolodies for the poor ASCII art] _______________ /------- WAN ----- \ / \ source router ---- | DMZ (dest) | \------- WLAN ----- / \_______________/ On Mon, 2003-01-20 at 11:45, Evan Borgstrom wrote: > That's not gonna work in my sitation. I guess I need to further explain > how I'm looking for traffic to flow. > > > If traffic is from the WAN bound for the DMZ then the return path needs to > leave the WAN. > > If traffic is from the WLAN bound for the DMZ then the return path needs > to leave the WLAN. > > So, I need to be able to mark the connection somehow as the inbound > traffic from the WAN is bound for the DMZ so that I can specify a > different routing table for the return path so that it will leave the WAN > as well, otherwise it might end up with a more specific route through the > WLAN which will cause problems. > > Does that make more sense? > > -Evan > > > If this traffic isn't LAN related then just do > > > > ip rule add from $WAN_IP table $TABLE_NAME > > > > ip route add default via $WAN_PEER_IP dev $WAN_IF table $TABLE_NAME > > > > This will add a source based route so that traffic entering on the > > $WAN_IF has its resonses exit on the $WAN_IF. > > > > See the Advanced Routing HOWTO for more info. > > > > Regards, > > > > PJ > > > > On Mon, 2003-01-20 at 08:35, Evan Borgstrom wrote: > >> I've got sort of a strange setup that I'm looking to accomplish some > >> strange async routing. I know how I want to accomplish it and am > >> pretty sure that I can do it with netfilter but just can't seem to > >> find the proper way. > >> > >> Here's the rundown on the network setup: > >> > >> [ LAN ] -- > >> [ DMZ ] -- [ Firewall/Router ] -- [ WAN ] > >> | > >> | > >> [ WLAN ] > >> > >> > >> The WLAN is between myself and a couple of other people in my building > >> to provide redundant paths out of each of our networks and is working > >> beautifully. We all advertise (via BGP) blocks close to us to each to > >> provide the shortest path as well. > >> > >> Comming from the WAN I have a /29 routed to the DMZ which services a > >> number of machines that provide different services. > >> > >> The firewall/router is a linux box that is running iptables. > >> > >> > >> Now the problem: > >> Because of the advertisments comming over the WLAN I now have about 40 > >> routes in the kernel routing table. Most of them are not very specific > >> since we advertise our ISP's blocks to each other, so I have routes > >> for /16's, /21's, etc... What happens is when someone that resides in > >> one of these blocks that I'm getting advertisements for tries to > >> access an address in my /29 their return path follows the advertisment > >> over the WLAN. > >> > >> Using the iproute2 package I've created a second routing table with a > >> single default route out my WAN default route. I'm hopping that > >> there's a way to tag the connection in the conntrack table and then -j > >> MARK it when a related,established packet comes back so that I use the > >> iproute2 package to specify that the second routing table will be > >> used. > >> > >> Anyone know of a way that I can accomplish this? > >> > >> Thanks in advance, > >> Evan > >> > >> -- > >> Evan Borgstrom <evan@unixpimps.org> > >> http://www.unixpimps.org - SIG:ILL > >> > >> > >> > > -- > > > > 'Conformity is the jailer of freedom and the enemy of growth.' - John F. > > Kennedy > > > -- > Evan Borgstrom <evan@unixpimps.org> > http://www.unixpimps.org - SIG:ILL > > > -- Some people wish to get what they deserve, while others fear the same. Homepage: http://www.wizardslair.net