Say you need to test your web server's basic connectivity to its SQL database server, or its Oracle database server, or its SMTP mail relay host, etc. You would want to hop on the web server, open a command line console (DOS prompt), and try to connect using telnet commands like:
Telnet myOracleServer 1521
What if you don't the necessary access to log on to the web server? That's the problem I have been facing. Our data center was outsourced, servers moved, and stuff stopped working. If your web application doesn't have the basic connectivity we all take for granted, it's not going to tell you your firewall rules are all mucked up; it's just not going to work.
Enter
SourceForge.NET's Telnet .NET library. Download this library, add it to your application's references, write a
simple web form that tests remote host and port combinations from user input, and you have a helpful diagnostics tool. It is presently saving my life.
