That’s the problem I’m really trying to solve. What it won’t do is kill off the session if the user walks away from their terminal for more than 5 minutes. So if you set the interval to 60 and the MaxCount to 5, then you have some clients unexpectedly die due to a power failure or become inaccessible due to a network outage, the session will be killed off on the server about 5 minutes later. This allows the client to respond over the channel that it is still alive and allows the server to clean up sessions where either the network connection has been interrupted or the client has died without gracefully disconnecting. If you set ClientAliveInterval to a non-zero value, the server will send ClientAlive messages over the encrypted channel if it doesn’t see traffic from the client for that many seconds. Unfortunately, this is not what ClientAliveInterval and ClientAliveMaxCount do. I am looking for a way to get the ssh daemon to enforce an idle timeout for users, which it seems many others are also looking for. This “solution” to set an idle timeout seems quite common on the internet, but it’s not actually correct. This is to prevent someone from walking by and hijacking your session when you are away for an extended period of time. $ sudo systemctl reload sshdĪs an SSH security measure, it’s always advisable not to set the SSH timeout value to a huge value. Once done, reload the OpenSSH daemon for the changes to come into effect. This is an equivalent of 1 hour, which implies that your ssh session will remain alive for idle time of 1 hour without dropping.Īlternatively, you can achieve the same result by specifying the ClientAliveInterval parameter alone. The Timeout value will be 1200 seconds * 3 = 3600 seconds. Timeout value = ClientAliveInterval * ClientAliveCountMaxįor example, let’s say you have defined your parameters as shown: The timeout value is given by the product of the above parameters i.e. If this limit is reached while the messages are being sent, the sshd daemon will drop the session, effectively terminating the ssh session. On the other hand, the ClientAliveCountMax parameter defines the number of client alive messages which are sent without getting any messages from the client. The ClientAliveInterval parameter specifies the time in seconds that the server will wait before sending a null packet to the client system to keep the connection alive. Scroll and locate the following parameters:

Putty ssh extend session