I’ve written about relaying TCP traffic using SSH port forwarding. Though sometimes you don’t require the authenticity and encryption of SSH or want to use another protocol such as UDP. That’s where socat comes in.

The following will listen to TCP traffic on port 8001 and redirect it to TCP localhost:8000

socat tcp-listen:8001,reuseaddr,fork tcp:localhost:8000

This will listen UDP on port 4009 and forward it to UDP localhost:4010

socat udp-listen:4009,reuseaddr,fork udp:localhost:4010