Communication between Windows application and WinCE application of c#.net over tcp

Question

I have developed 2 applications. One is the windows application (main application c#.net) that receives the data through tcp communication (tcpclient and tcplistener classes used). Other application is written in Windows smart device environment using c#.net. This will send the data to main application and receive the response from main application. I am getting an error "A socket operation was attempted to an unreachable host" while trying to connect to main application from WinCE smart device application. I have checked all the network setting and the firewall setting and found ok. The same operation is successfully done through windows application but not through smart device application. Can anybody help me to solve this error?