UDP broadcasting

Hi, I’m trying to get a basic IP-based network running between 2 or 3
USRPs
and I’m having trouble trying to send broadcast UDP packets via
dial_tone_sink.py in the network examples. I’m sending the packets
addressed to 192.168.200.255 with port 0 but this continuously results
in a
“can’t open socket” error. If I address the packets directly to another
machine 192.168.200.30, it works fine. Is there something else I need
to do
to broadcast packets?