Dear All, Am just taken an example from http://libcli.sourceforge.net and integrated into my eCos application. Am creating a thread, under that am calling TELNET_start() (can see in clitest.c). which is accepting the telnet sessions. and after that its calling the cli_loop(). But when i issue quit, which exits the while loop in the cli_loop() function and tries to close the sockfd. But this is not sending the FIN my embedded system to my PC telnet client. I also set the SO_LINGER socket option. Could you please help me out. My source code is attached here with the libcli.c for your reference. best regards, srinivas.