ssh server: reasons for sudden "Connection closed by remote host"
One of my ec2 servers has stopped receiving ssh connections. The OS is Ubuntu server 8.04, and the ssh server is the standard
After months of uptime, I tried to connet to it today, and got the following message:
ssh_exchange_identification: Connection closed by remote host
Any idea what could have went wrong?
Update: After a reboot, the server started receiving new connections. Disks are below 50% usage.
Now that you once again have access, check the log to determine what, if any, clues there are as to why you were blocked.
tail -n300 /var/log/auth.log | grep ssh 1
The other thing to remember is that, if it happens again, you can run
sshin verbose mode with the
-vvvoption, which will return more detailed diagnostic information. From
-v Verbose mode. Causes ssh to print debugging messages about its progress. This is helpful in debugging connection, authentication, and configuration problems. Multiple -v options increase the verbosity. The maximum is 3.
 You may need to increase/decrease the amount you tail by (
-n) to identify the relevant entries.