Network again!

Peter Garrett peter.garrett at optusnet.com.au
Mon May 28 07:55:57 UTC 2007


On Sun, 27 May 2007 23:34:27 -0500
Avi Schwartz <ubuntu-users874 at cfftechnologies.com> wrote:

>  am not sure what are you trying to do.  You are trying to connect to 
> port 22 which is SSH (secure shell) via telnet which obviously doesn't 
> know the SSH protocol therefore the errors you see.
> If you want to connect via SSH then use the ssh client.

He is using a common testing method, and it should work if the server is
running. For example:

$ telnet altwifi 22
Trying 192.168.1.102...
Connected to altwifi.
Escape character is '^]'.
SSH-2.0-OpenSSH_4.3p2 Debian-8ubuntu1
^]

telnet> quit
Connection closed.

The same technique works to connect to any server - smtp, apache etc etc

$ telnet mail.optusnet.com.au 25
Trying 211.29.132.250...
Connected to mail.optusnet.com.au.
Escape character is '^]'.
220 mail24.syd.optusnet.com.au ESMTP Sendmail 8.13.1/8.13.1; Mon, 28 May
2007 17:50:51 +1000

and so on. The fact that the protocol is not telnet is irrelevant -
provided the port is correct, telnet will connect as above. Of course,
with ssh you can't go any further than just a connection, obviously.
Telnet will still often tell you what server you are dealing with, as you
see above in the smtp example.

Peter




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