I have an application which occasionally leaves an entry in the output of the netstat command which indicates a UDP socket is associated with a port on another machine, and the state that the netstat command reports is "established".
To my understanding, this does not make sense -- UDP is a connectionless protocol, right?
When this happens, the program will fail to restart. I think the connection is associated with an RTP session which is set up and (supposedly correctly) torn down when the application exits. The failure on restart is clearly related to this persistent "connection" -- the RTP component is what fails to start.
I'm running linux, Ubuntu 9.04 distro.