Hi Dennis,

> I have upload one new screenshot:

no need for an image for such short information - you could have simply c&p the parts here

"netstat -rn" is for printing the current routing table, thus grep'ing for the port number is counter-productive

You have not yet really described your test setup, so I'm still guessing. I cannot tell if the UDP sender is on the same host or elsewhere. Might be irrelevant (see next line), but you need to provide a more detailed description in order to have others analyze complex networking problems: It's about tracing the packet flow in one's mind. Sender (complete IP configuration including routing table, firewalling, IP stack config...), intermediate network, receiver (again complete information). You may leave out information if it seems obvious or definitely unrelated, but in the current case, too much is left open

Back to suggestions: What happens when you bind netcat explicitly to the proper IP? Even netcat's documentation mentions possible quirks when listening to UDP on multi-homed machines...

Regards,
Jens