No route to host error

[max22]

i'm trying to write a program that sends a file from a client to server, compile it and send it back. The program works well on a single laptop, where the server and client r run in separate terminals and the IP used to send and recv are the same ethernet address. But when i tried in two different laptops, the file is being sent, compiled, but the server is not able to establish a connection to return the file. The following error occurs
connect() failure : no route to host

I checked the cables and the physical connections. There is no problem. The same port is used for sending/recving. I cant understand the fact that..a file can be sent from 1 to the other but not the other way round. Is this due to some kind of firewall rules on one of the laptops? Somebody pls help me with this.

[anomie]

Try netstat -rn on the box that is getting the 'no route to host' error, and post the results.

You probably need to specify an appropriate default gateway.