没有连接到C＃中的服务器问题

I am running a client/server application. I use a textbox to let the user type in the IP address and port. I try to connect to the server, using 127.0.0.1 and there is no problem. After that I tried using 192.168.2.102 (NAT ip address of this computer), and it fails. Any idea why?I am running a client/server application. I use