Alternate route for port 80

[Onur Aslan <onuraslan@gmail.com>]

Hi.

I want to use my vpn for outgoing port 80 connections in my Debian router.

My current route table:

    # ip route
    default dev ppp0  scope link 
    95.9.x.x dev ppp0  proto kernel  scope link  src 95.9.x.x
    192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.1 
    192.168.2.0/24 dev wlan0  proto kernel  scope link  src 192.168.2.1 
    192.168.4.0/24 dev tap0  proto kernel  scope link  src 192.168.4.2


tap0 is my virtual vpn device created by openvpn. When I use something like
that all my traffic going through by vpn, so vpn working fine:

    # ip route
    default via 192.168.4.1 dev tap0 
    95.9.x.x dev ppp0  proto kernel  scope link  src 95.9.x.x
    192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.1 
    192.168.2.0/24 dev wlan0  proto kernel  scope link  src 192.168.2.1 
    192.168.4.0/24 dev tap0  proto kernel  scope link  src 192.168.4.2 
    199.180.x.x dev ppp0  scope link


199.180.x.x and 192.168.4.1 are IP addresses of my vpn server.

Now, I want to use an alternate route for only port 80 outgoing
traffic. I create a table and set default gateway for this table with:


    # echo 10 alter >> /etc/iproute2/rt_tables
    # ip route add default via 192.168.4.1 table alter


And I create a fwmark and mark OUTPUT requests with:

    # ip rule add fwmark 0x10 table alter
    # iptables -t mangle -A OUTPUT -p tcp --dport 80 -j MARK \
         --set-mark 0x10


In my theory this should work, but it's not working. When I use that I am
not able to connect any website. What I am missing here? What should I add
to my alternate routing table to make it work?

Btw I tried to send this to debian-firewall but I got quota exceed error.

Thanks.