W5100 problem connecting to remote server

I am connecting an LPC1768 to a WIZ5100. I can connect to a host on my local subnet, but when I attempt to connect to a remote host the connection fails. I see the ARP to the gateway and the gateway responds, but for some reason the connection is never established. I am able to telnet to the remote host via the same connection that the 5100 is using without any problems.

The IP is for the 5100. The IP of the server I am able to connect to is and the IP of the server I am not able to connect to is
I can ping the 5100 from the local network. I am able to properly connect and send and receive from the local server. I am not able to send and receive ONLY from a remote server. I disconnect the 5100 and set the IP of my PC and the connection to the remote server is Ok
Do you have any suggestion to do ?
There is un upgrade firmware to solve this problem ?

You set the gateway address (registers GAR0/GAR3) , subnet mask (SUBR0/SUBR3) and mac address (SHAR0/SHAR5) into the W5100?

The gateway address is the sub net mask is the Mac address is {0x00,0x08,0xDC,0x01,0x02,0x02}

The 5100 send the message to the gateway but remaine indefinitelly in the SOCK_SYNSENT Status

I can give you a further indication, I think the problem may be related to NAT because using a VPN connection is working properly


I am also having same problem. I applied all the noted comments from here to my system (setting gateways etc.,)
but I am still having problem with connection.

How did you solve connecting problem with VPN?
I am not familiar with VPN environment. Could you give me detailed guide on how you solved the problem?

Thank you very much!!