UDP Broadcast Packet Relay

This program listens for packets on a specified UDP broadcast port. When a packet is received, it sends that packet to all specified interfaces but the one it came from as though it originated from the original sender.

The primary purpose of this is to allow games on machines on separated local networks (Ethernet, WLAN) that use udp broadcasts to find each other to do so.

It also works on ppp links, so you can log in from windows boxes (e.g. using pptp) and play LAN-based games together. Currently, you have to care about upcoming or downgoing interfaces yourself.


cp udp-broadcast-relay /some/where


/some/where/udp-broadcast-relay id udp-port eth0 eth1...

udp-broadcast-relay must be run as root to be able to create a raw socket (necessary) to send packets as though they originated from the original sender.



/some/where/udp-broadcast-relay -f 1 6112 eth0 eth1  # forward Warcraft 3 broadcast packets


Over the last years, various people submitted code to the project. Note that I do not use udp-broadcast-relay any more myself, so these changes were not tested by me.

Thanks to all contributors!




This is based upon udp_broadcast_fw by Nathan O'Sullivan.

HISTORY of udp_broadcast_fw


This code is made available under the GPL. Read the COPYING file inside the archive for more info.