[cs631apue] Testing the server

[Jan Schaumann]

Paul-Anthony Dudzinski <pdudzins at stevens.edu> wrote:
> Is anyone else having a hard time using telnet to connect between different
> scrit labs (smurf and nemo)?

That should work.  You can test this by using the nc(1) command.  For
example:

smurf$ nc -l 12345

nemo$ telnet smurf 12345
Connected to smurf.srcit.stevens-tech.edu.
Escape character is '^]'.
hello


Remember that telnet uses TCP, so if you're testing with a UDP server,
then telnet won't work.  nc(1) can be used to connect to a UDP server,
though:

smurf$ nc -u -l 12345

nemo$ echo hello | nc -u smurf 12345


> I am trying to use to test my web server. I can get a connection on
> port 22 though...

That's the ssh daemon listening.

Also remember that you cannot open a port <1024 unless you're the
super-user.

Finally, you can see what ports are open on a system using netstat(1),
for example.

-Jan