I'm making a Chat Program using UDP. The UDP port the messages are broadcast on is 51345. The problem is, on the LAN I tested the program on (Stations 1-4):

1) Station 1 sent messages which only Station 2 picked up.

2) Station 2 could not reply to Station 1's messages.

3) Stations 3&4 couldn't do anything!!

Is this because of UDP port configuration on the 4 Stations being different, or what?

It is a sample app supplied with a Power TCP control, which I have customised slightly, but the part which sends messages etc has not been touched.

Help Please!!