UDP communications failure after period of inactivity

[DSGarcia]

I have a VB.NET application that receives messages using UDP. The sender of the message is a special micro-controller and the PC running the .NET application is used as an user interface and data logger. This application is installed at several locations and works everywhere fine except for two particular computers. The two installations where there are problems are computer-dependent. I.E., the problem is with two particular computers and changing them out makes the problem disappear.
If the program is started and the computer receives transactions regularly, there are no problems. However, if there is a period of inactivity, the computer does not receive the message when it eventually comes. I can 'ping' the controller from the computer, but I must exit the program and restart for it to work again. What can be special about these two particular computers? All are running Windows XP.
Thanks,
Dale

 

[zekeman]

Long shot:
What OS are the two machines running? Can you configure the
Network connections?

See this article about network command line tools:
http://commandwindows.com/netsh.htm