Setting the time link limit for SSH server under Linux

OpenSSH for security reasons, if a user is connected to an SSH server for a period of inactivity, SSH server will automatically terminate the SSH connection after a certain amount of time has passed. I am accustomed to long-time connection, need to make the following changes:

1. Open SSH config file: # vim/etc/ssh/sshd_config
Add the following two parameters to save it:

Tcpkeepalive Yes
Clientalivecountmax 360

Note: The previous parameter indicates that you want to keep the TCP connection, and the latter parameter indicates how long the client's SSH line is idle and automatically terminates the value of the connection in minutes.

2. Restart sshd in effect:

/etc/init.d/sshd restart

Note: This method applies to all Linux distributions for OpenSSH.

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For security reasons, if the user is idle after connecting to the SSH server, SSH server will automatically terminate the SSH connection after a certain period of time. Here's how to set the terminating connection time:

1. Open the/etc/ssh/sshd_config file, there is a parameter of Clientalivecountmax, that is, if the client does not have a corresponding, then determine a time-out, this parameter set the number of times allowed to timeout.

2. If the line is preceded by the # number, remove the # number and modify the desired number of times, such as 5.

3. Find the Clientaliveinterval parameter, do not add to themselves, this parameter is to set the user side of the SSH connection idle for a long time after the number of automatic termination, in seconds, can be set 300 seconds, that is, 5 minutes. The two parameters together are 25 minutes to terminate the connection.

4. Save and close the file after modification, restart sshd:

/etc/rc.d/init.d/sshd restart

Setting the time link limit for SSH server under Linux