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What do you need to know about autossh?
Autossh is a program to start a copy of ssh and monitor it, restarting it as necessary should it die or stop passing traffic.
How often does autossh try to restart SSH?
Periodically (by default every 10 minutes), autossh attempts to pass traffic on the monitor forwarded port. If this fails, autossh will kill the child ssh process (if it is still running) and start a new one; 5. If the child ssh process dies for any other reason, autossh will attempt to start a new one.
How often does autossh try to pass traffic?
If autossh itself receives a SIGTERM, SIGINT, or a SIGKILL signal, it assumes that it was deliberately signalled, and exits after killing the child ssh process; 3. 4. Periodically (by default every 10 minutes), autossh attempts to pass traffic on the monitor forwarded port.
What’s the change in autossh version 1.2?
With version 1.2 of autossh the method changed: autossh uses ssh to construct a loop of ssh forwardings (one from local to remote, one from remote to local), and then sends test data that it expects to get back. (The idea is thanks to Terrence Martin.)
How does autossh work on a SSH connection?
AutoSSH and -M (monitoring port) With -M AutoSSH will continuously send data back and forth through the pair of monitoring ports in order to keep track of an established connection. If no data is going through anymore, it will restart the connection. The specified monitoring and the port directly above (+1) must be free.
How can I install autossh on my computer?
How to install AutoSSH on various systems via their package manager. Alternatively you can also compile and install AutoSSH from source: Note: Make sure to grab the latest version which can be found here: http://www.harding.motd.ca/autossh/. Ignore -M for now.
What should autossh be set to at boot time?
Setting AUTOSSH_GATETIME to 0 is most useful when running AutoSSH at boot time. All other environmental variables including the once responsible for logging options can be found in the AutoSSH Readme.
What’s the difference between auto SSH and F SSH?
The -f flag is stripped from arguments passed to ssh. Note that there is a crucial a difference between -f with autossh, and -f with ssh: when used with autossh ssh will be unable to ask for passwords or passphrases. When -f is used, the “starting gate” time (see AUTOSSH_GATETIME) is set to 0.