There is no need for marking the packets. A simple rule associated with a default route (in different tables) does the trick: # this takes care of the main default route through your cable access ip ro add default via <IP of upstream cable router> dev eth0 # these take care of the outgoing traffic from ppp0 ip ro add default scope global dev ppp0 table 100 ip ru add from 208.31.142.43/32 table 100 # these take care of the outgoing traffic from ppp1 ip ro add default scope global dev ppp1 table 101 ip ru add from 208.31.142.23/32 table 101 # reset the cache ip ro flush cache Keep in mind that the routes you want to set up are _only_ used for the outgoing traffic. You have no control whatsoever for the incoming traffic. But I guess it's pretty obvious... Ramin On Fri, Jun 06, 2003 at 10:12:49AM -0400, Paul Miller wrote: > Sorry this is so long, I wanna be specific. > > I've got a routing issue that I think should be really easy > to solve. It's baffled me for over 4 hours now, so I'm > going to ask. > > eth0 - my cable internet 24.247.240.235 > ppp0 - 208.31.142.43 > ppp1 - 208.31.142.23 > > My employer makes money for having my modems connected. > That's a long story, and hard to explain. Anyway, ppp0 and > ppp1 are just sitting there doing nothing. > > The other day my cable went out, and with it, my default > route. I tried to telnet into my ppp devices, but they > didn't work because the return path was trying to go through > the cable. > > Even when the cable is working, I can't telnet into the ppp > devs unless I make a specific route. > > route add 208.31.142.2 gw 208.31.142.43 dev ppp0 > > That may look odd, trust me, my ip is my gateway. Anyhoo, > after that it works great. That's less than desireable > though -- then all traffic to my webserver goes through > ppp0. What I really want, is any traffic that SYNs to > 208.31.142.43 from the outside, should automagically route > back out that device. I hope that made sense. > > So, I tried to mark the packets with 0x04 then route them > based on that... > > iptables -t mangle -A PREROUTING -p tcp -d 208.31.142.43 -j TOS --set-tos 0x04 > ip route add default via 208.31.142.43 dev ppp0 tos 0x04 > > I've had success routing on those tos values before. But > this solution didn't work for obvious reasons. I need to > mark the whole session, not just packets that are destined > to 208.31.142.43. > > Questions: > > Is there a way to mark the entire session in such a way that > I can do sorta this type of routing? > > Is there a cleaner way to make sure that: > > a) my default route for anything starting from my box goes > out the cable modem... > > b) any traffic initiated to one of the ppp devs > automagically routes back out the same ppp dev? > > > -- > If riding in an airplane is flying, then riding in a boat > is swimming. 33 jumps, 6.7 minutes of freefall, 14.4 ff vertical miles. > Key fingerprint = CEAC EBBE C541 B1E0 3174 81E0 E4E5 4D11 9A0C DA99
