ssh client times out to some servers, works on others

Posted by mmdanziger on Ask Ubuntu See other posts from Ask Ubuntu or by mmdanziger
Published on 2012-12-10T11:23:15Z Indexed on 2012/12/10 11:23 UTC
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Filed under:

ssh

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firewall

|

timeout

I have a strange problem and I'm not sure where to begin. My ssh client works on some servers but times out on others.

Obviously, I checked that the servers are accessible via ssh from other locations. From my machine A I can log on to C only by logging on to B first. There are at least two servers for which this is the case. To make matters more strange

sudo ufw status -> Status: inactive
nmap -sT -p 22 <problem_server> -> ...22/tcp open ssh...

On one affected server I am getting: ssh_exchange_identification: Connection closed by remote host and on the other I am getting ssh: connect to host <problem_server> port 22: Connection timed out

With both of these servers I can log in from other machines. How can I troubleshoot such a problem?

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