Arduino + Official ETH Shield UDP Broadcast

Is it possible for the Arduino to do a UDP Broadcast? and if so, how? I'm interested in creating a two way communications system that allows for broadcast messages to be sent to monitoring computers. I have 2 way comms working, but is only capable of unicast (1 computer, 1 arduino communications)

Hey gmxx,

To broadcast a UDP message on a local network, just send it to the IP address "". I haven't tried this with a router yet, but it works fine on Win7 64bit and an Arduino Duemilanove with the official Ethernet shield (Wiznet W5100). I was able to change the IP address of my Windows machine, and it still received the messages just fine.

Chris K