ConnectToTCPServer returns -11(timeout) even though host appears to exist

[JoeCVI]

I've been having some problems with ConnectToTcpServer on a windows 2000 network. I have Client/Server apps built in labwindows(measurement studio 6.0)

Part of the problem is that some of the Host Servers are mobile(laptop) and may appear on different wireless nodes within the LAN. DHCP is being used to ip addresses.

It appears that the ConnectToTCPServer call may be using "stale" hostname to IP resolution. The timeout occurs even if I set the timeout value arbitrarily large. I've verified that the CVI Server is in fact up and running in all these cases. And I have verfied in these cases that I can successfully PING the server by hostname(using a dos prompt on the client. So some layer of th
e name resolution seems to be working from the windows point of view.

Any ideas?

[Woolie Willie]

What port are you using? IMCP which ping uses is not the sames as opening a TCP port. Is there a router or firewall in the picture that may be blocking the port you are trying to use?