UDP read/write on Arduino Industrial 101

Hi all,

I have been doing UDP based networking on linux but I am new to arduino. I recently bought arduino industrial 101 because I wanted to make one of my JAVA applications running on my linux to be portable.

I created a simple python script and copied it to linino that send a string and receives a reply. When I run this I can receive the message from arduino but cannot send the reply. I get port unreachable message on wireshark.

I also tried to send messages using "packet sender" and read the communcation on wireshark and I see the same error: Port unreachable. I am using port 20777 if that really matters. I tried doing telnet and while I can telnet to port 80 (webserver) I cannot do it to any other port.

I checked iptables and everything is open and seems ok.

Please, can anyone help in this regard?