Hi Mike, you've got some useful stuff to try from others in the thread.
When you're changing sshd_config you're restarting sshd afterwards?
>From an Internet-based Linux host, does "nc some.dyndns.org
<http://some.dyndns.org> 2222" produce an openssh banner?
My next steps would be ssh -v on client side and a simultaneous
multitail on /var/log/auth.log on the server.
When running Internet-facing ssh it would be prudent to look into
running some means of defence against the inevitable intrusion
attempts. Look at DenyHosts and fail2ban - both are packages in
Ubuntu/Debian.
Security through obscurity may be scoffed at but imho it's a good way
to counter unstructured attacks.
Thanks Imran and to others for the great advice. I will be going through
all the posts. However, what I would really like to understand is why
does simply changing the port number and nothing else render the server
inaccessible?
Kind regards
Mike
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