I want to forward all the locally generated traffic on a dummy interface to ppp interface.
Since PPP interface is dynamic (comes up and goes down based on connected devices), my process binds to the dummy interface and sends traffic through it.
I have created a separate routing table with the following rules:
ip rule add oif dummy0 table rt_dummy ip rule add from source <dummy0-ip> table rt_dummy ip rule add fwmark 100 table rt_dummy
Default route of the routing table is through ppp interface
ip route default dev ppp0 table rt_dummy
iptables -t nat -A POSTROUTING -s dummy-interface-ip -o ppp0 -j MASQUERADE iptables -t raw -A OUTPUT -s dummy-interface-ip -j MARK --set-mark 100
But still packets are NOT going through ppp0 interface