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Would anyone be kind enough to give me some pointers to route packets from a specific ip on my subnet via the tun0 OpenVPN interface, and all other hosts out the default route of the main routing table (192.168.1.1 on br0)?

i.e. 192.168.1.2-9 -> via br0, and 192.168.1.200 -> via tun0

I am masquerading on tun0 as i will be routing a number of hosts through the router: iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE

I have created the tables:

mkdir /etc/iproute2
echo 201 table1 >> /etc/iproute2/rt_tables
ip rule add from 192.168.1.200/32 table table1

But i am really stuck from here. I tried adding default routes in the table1 but all traffic stops at this point (i am pinging from the host 192.168.1.200 out onto the net, it works as soon as this command below is entered it times out):

ip route add 10.19.0.5 dev tun0 scope link src 10.19.0.6 table table1 (not sure if this is needed - either way doesnt work with or without)
ip route add default via 10.19.0.5 dev tun0 table table1

I did try: ip route add default dev tun0 table table1. and again that fails to work. I appreciate this isnt a guessing game hence moving to post here in hope of some expert advice.

Routing table for the main table (table 1 contains the entries from above commands):

root@OpenWrt:~# ip route list table table1
default via 10.19.0.5 dev tun0

root@OpenWrt:~# ip route list table main
10.20.30.40 via 192.168.1.1 dev br0
10.19.0.1 via 10.19.0.5 dev tun0
10.19.0.5 dev tun0 proto kernel scope link src 10.19.0.6
192.168.1.0/24 dev br0 proto kernel scope link src 192.168.1.4
default via 192.168.1.1 dev br0

There is a point to point link to the OpenVPN server on 10.19.0.5 with a local address of 10.19.0.6, but im not sure if this needs to be added in the table1? I did try by adding ip route add 10.19.0.5 dev tun0 scope link src 10.19.0.6 table table1, but again still the same issue.

With OpenVPN setup to push the redirect-gateway option, all works well with the routing table and the box acts as a router sending everything through it (table shown below - this works fine apart from everyone is routed through it). As mentioned, I would like the tables default route below to only apply to the host 192.168.1.200. I am posting the table below as this does work for all hosts:

Many thanks in advance

(Last edited by g18c on 11 Jul 2007, 12:38)