i installed linux 2010 mandriva on a (embeded) system,and i run several server programs on it that accept connections from clients. clients are connected to server(s) and every things is ok, but when i go to home and back to my work tomorrow, i see no data can be sent to server programs and this problem exists until i restart the server programs or reconnect tcp client programs. this problem occurs even when both client and server programs executed on the same (embeded) system.why this happens? i checked by netstat and see that server ports exists in the list(and not closed by kernel) but it seems kernel or an application above it prohibit data transmission.i changed the OS and installed ubuntu but the problem exists.
thank you for helping.

if your client use ssh to make connection to server, make sure the server sshd_config uncomment TCPKeepAlive yes
and reload sshd .

or what is the protocol use by client to connect to the server, answering this might easy for other people to answer

clients connect to server with tcp or udp connections and in either case, the problem exists. if client with udp connection connect to server we must restart server program and if client use tcp connection, we must restart client program for establishing a new connection to server.

while waiting the answer from others could you let me/us know the program you use on client and server if it opensource
because i will try to setup on my lab, btw if the program is the commercial program , i suggest you contact the support directly

the programs on client and servers are not important,every program that use a socket(tcp or udp) failed too keep communicating after a period. for example if we put a program on server that replies to client request via a udp connection, after a period, if we send a request from client to server for accessing some data,server program does'nt reply and we must restart it.
with thanks.

ok i just blindly guess check your client/lan network if possibility of overloaded
eg. unproper torrent run on the local network,