I am using the following command to establish a reverse ssh tunnel with an ssh server

The server is rebooted every night and the tunnel is established automatically on reboot successfully every time.

What I need to do, is run a check, and if for some reason the tunnel is not established, I want to log it in a log file.

How can I reliably check if the tunnel is up or not?
Keep in mind that other ssh sessions might be active at the time, so I don't want the checking method to pick up any of those successful sessions. It has to check only the tunnel.

Thanks

The script I posted here uses two checks.
1. Check if the process started by the ssh command is running.
2. Test if there is a listening process on the remote host.

I'm looking for something that will check if there is an active tunnel connection.

The two checks you mention are useful, but don't actually check if there's a tunnel up and running.

Do realize using the root account over any network is not a Best Practice.


Use autossh instead then check its log file?

The second check tries running a command on the remote host, which requires an operational tunnel to complete successfully.