UDP port scanner

[jadams]

All the scanners I can find are for TCP. The one I can find is producing sketchy results, says every UDP port in the range i ask it to scan is open. This cant be.

 

[CaseyBlackburn]

It's sort of a limitation with the way UDP works. TCP works better because of the way the traffic goes through certain steps. UDP at times seems like you are just throwing information out there and hoping it arrives in one piece.

Maybe this will help explain it: http://en.wikipedia.org/wiki/Port_scanner#UDP_scanning

 

[jadams]

A game server I'm running connects through UDP ports and people cant connect over the internet, however I can connect through the LAN. First thought that came to mind is port forwarding. But nowhere can I test if a UDP port is open. Maybe VZ blocks incoming UDP ports?

 

[CaseyBlackburn]

You could see if your router is the issue by doing this:

Game server -> Router -> (another network switch, crossover cable, or auto-sensing NIC port) -> Another computer.

Assign your WAN port on your router to a static IP of 1.1.1.1/255.255.255.0. Assign the other computer a static ip of 1.1.1.2/255.255.255.0. On the other computer try to connect to your game server at 1.1.1.1. That way you'll be testing if traffic is going through your router and you take the ISP out of the mix.

 

[jadams]

Very true, I've done that before. Shoulda thought of that. Thanks!

 

[Berg0]

or use wireshark.