xdmcp and netstat

On my linux box, i run netstat -l and i see xdmcp in the list but it doesn't have LISTEN as its state, see what it shows below, I'm wondering if this might explain why i can't see it in my exceed broadcast listing of servers broadcasting on our net? My unix boxes don't show this at all.

Proto Recv-Q Send-Q Local Address Foreign Address State
udp 36800 0 :xdmcp *:

what does this mean? is xdmcp supposed to be using the udp protocol? not tcp?

xdmcp is supposed to be udp just as you have it.

Very few of our unix systems have it either. But a few do. They need to be running X to have that socket open. A remote Xterminal will contact that socket to establish an X session. So any box with that socket is ready to manage remote x terminals.

xdmcp = x display manager control protocol
or something like that.

I don't understand the "broadcast" part of your question, so I'll have to pass on that.