Ethernet shield w5100 problem

Hello everybody! i got a little problem with my ethernet shield. The thing is that my shield can easily read RX data coming from my LAN, ex: 100.100.100.113 (computer) send data to my arduino at 100.100.100.118 on port 2222. Everything works perfectly here. but the thing is that if i send data through internet to my ip. ex: xxx.xxx.xxx.95 on port 2222..my ethernet RX led flash but data aren't appearing on the Serial terminal.

Now you will think! oh this dumbass doesn't make any port forwarding! But yess i do! The RX LED flash but nothing appear on my serial terminal. I am using the UDPSendreceiveString sketch and send data through a computer with UDP packet software.

I don't know what to do. I was able to do that some times ago..

I try the sketch with pachube.com and data are coming in! But it's tcp. So tcp work but not UDP in RX with data coming through internet and in local network it works!

Please help me!!

Thank you!

I am using the UDPSendreceiveString sketch and send data through a computer with UDP packet software.

Are your sure your router supports UDP port forwarding? Many routers don't support this, they only know TCP. What client do you use to send the UDP packets from the internet?
The flashing RX LED could also mean that there is some ARP traffic.

yes my touter support udp packet forwarding. its a cisco linksys e3200. and its not arp traffic because the rx led flash when i press enter on the udp tool on my computer. the led flash as i send the packet. like when you send data through the serial port. the tool is udp test tool.

thanks

Have you tried to sniff the traffic using a tool like WireShark?

its not arp traffic because the rx led flash when i press enter on the udp tool on my computer

Why does that prove that it's not ARP traffic? Do you know what ARP is for?

In excess of the IP address and port number, what else have you changed in the UDPSendReceiveString example?

Yeah i read about ARP traffic. Maybe it's that but only the RX led flash so..if it's ARP it is supposed to send a anwser so the TX would normally flash!??

And i try 3 arduino..2 uno..one due..i tried two ethernet shield..and the same problem with every combinaison. I didn't modify the program, only the port and ip for test purpose..My router is set to forward traffic on the good ip, with the good port!

Maybe it's arp traffic..but...what can i try now?

thanks

ok i've found the solution! The problem was that no gateway and subnet ip was in the sketchm, i added it and the sketch works, PERFECTLY!

Thank you for your anwser you make me learn about ARP traffic too!