I have an client application that is unable to connect with it's server counterpart over a VPN connection. Server is Windows SBS 2011, client is Windows 7 64bit Enterprise. Using Windows VPN client. I can ping the server and browse it's drives, but when the client application attempts to connect it fails immediately with a series of generic reasons (e.g. "Maybe the server isn't on" and "Maybe you are specifying an invalid IP address"). After speaking with the application support people they had me run a testing client/server pair of apps on the server and workstation to verify UDP traffic was being transmitted. The test failed.
So now I need to figure out whether or not UDP traffic is passing through, and if not what I need to do to resolve that.