You could write an interactive login sequence. For example your server sends the text line "Enter your authorisation" immediately when a client connects, then evaluate the first newline terminated response from the client. However, this simple approach works with most telnet clients only on a non standard port (other than port TCP 23)... I would strongly recommend to implement the full telnet protocol or at least look for IAC sequences in the server code (RFC 854). Hope this helps.

mhetfield1978 wrote: No...I'm unsing C programming Then you are in the wrong forum. This one's for .NET based C++ questions. Regards, Nish Nish’s thoughts on MFC, C++/CLI and .NET (my blog) C++/CLI in Action (*E-Book is out, Print version April 6th*)