====== Listening ======
<code>
# gnu-netcat
nc -lu -p 9999

# all other netcat's
nc -lu 9999
</code>

====== Broadcasting ======
<code>
echo poo | socat - UDP-DATAGRAM:192.168.1.255:9999,broadcast
</code>

====== Unicast ======
<code>
echo poo | nc -u 192.168.1.18 9999
</code>