I'm trying to send certain port traffic through my ppp0 interface it's a pptp vpn tunnel,

First, I'm using a wireless usb interface, I connect up to my access point, then I initiate my vpn, there is a connection but I do not channel all connexions through that, nor do I want to, so, say I want to channel all port 80 packets through my vpn (interface dev ppp0).

I first run:

iptables -t mangle -A OUTPUT -p tcp --dport 80 -j MARK --set-mark 0xa

to mark the correct packets then I add a table named vpn_table, I then add

ip route add default dev ppp0 table vpn_table

when I do that traffic begins to dribble through the ppp0, but no pages load. I supose I must have caused some sort of coflict, or the route I'm adding in vpn_table isn't quite right.

I'm not sure, I think I'm marking the packets correctly but I can't be sure of that either.

UPDATE: I think i've got part of the issue solved: running tcpdump -i ppp0 showed me that indeed there was outgoing requests via ppp0, now, there is never a response, and pages do not load with using that interface..i'm still missing something.