If this threshold is reached while server alive messages are being sent, ssh will disconnect from the server, terminating the session. Sets the number of server alive messages (see below) which may be sent without ssh(1) receiving any messages back from the server. These settings will make the SSH client or server send a null packet to the other side every 300 seconds (5 minutes), and give up if it doesn’t receive any response after 2 tries, at which point the connection is likely to have been discarded anyway. You can also make your OpenSSH server keep alive all connections with clients by adding the following to /etc/ssh/sshd_config: To enable the keep alive system-wide (root access required), edit /etc/ssh/ssh_config to set the settings for just your user, edit ~/.ssh/config (create the file if it doesn’t exist). In your session properties, go to Connection and under Sending of null packets to keep session active, set Seconds between keepalives (0 to turn off) to e.g. To avoid having your SSH sessions become unresponsive after e.g. 5 minutes, do the following: Sometimes the interval between session drops is 24 hours, but on many commodity firewalls, connections are killed after as little as 300 seconds. Many NAT firewalls time out idle sessions after a certain period of time to keep their trunks clean.

Ssh tunnel keep alive