hi,

i have written a client/ server program in linux & windows to send messages to & from both

when i use the windows client to connect the linux server it is able to connect , but when i try to connect the linux client to windows winsock control from linux the connection times out.
but the same linux client connects to the linux server.

do i have to do some other settings for the linux client to connect to the windows pc.

the windows client & server is in Visual Basic 6.
and in linux i have written the client & server in C++

Are you using Windows XP? It has firewall settings. You can disable them completely or create an open port for your messaging software within it.

i have added the port in windows firewall setting , when i am using tcpview to view connections it shows that the connecton has be established but data transfer does not take place.

Sockets are absolutely a good, 100% platform-independent way to communicate between any two hosts, regardless if one happens to be Windows and the other Linux.

The best way to proceed is:

1. Code a C client that can be compiled for both Windows and Linux
(although TCP/IP itself is 100% platform-independent, you'll need a few #ifdef's
to accomodate the difference between Winsock and Linux sockets).

2. Run the client locally, on the same host as the server (using loopback address 127.0.0.1).

3. Once the application is working locally, it should also work the same way remotely.

If they weren't connecting at all (and you're sure the two hosts could "ping" each other), firewalls would indeed be my first guess.

But based on what you're saying, it sounds like your Windows client/server pair is in some way incompatible with your Linux client/server pair.

Hence my strong advice: code up ONE client you can test in BOTH environments (with a simple recompile).

IMHO ...

Thanks a lot all of you,

The problem was due to firewall only,
Thank you for all your help