Specific port routing

[sgp729]

I'm trying to proxy not all traffic but only packets with certain ports, I mark the packets I need but have no idea how to route them to the correct gateway:

iptables -t mangle -A PREROUTING -p udp --dport 50000:65000 -j MARK --set-mark 0xB

The desired behavior is: route packets marked with 0xB through dev tun0
How can I achieve this?

[xjasonlyu]

Interesting, I've never done this before, but it's theoretically feasible... 🤔