Linux - netcat aka nc

So for some reason some of our VMs dont seem to be able to deliver their collectd data to the graphite VM.  So I wondered about port blocking..

Ran the following commands:

SERVER:
  nc -lu 25827

CLIENT 1:
  echo 'test1' |nc -u -w1 thatServer 25827
CLIENT 2:
  echo 'test2' |nc -u -w1 thatServer 25827