CentOS keeps linux servers connected by SSH offline

When you use ssh to connect to a remote server, if you do not perform the operation for a long time, the remote connection may be interrupted. Buffer data such as executing programs and vim will be lost.

SecureCRT

Use SecureCRT to connect to the remote server, and select send protocol NO-OP in session Options> terminal settings ".

Use putty to connect to the remote server and find Connection-> Seconds between keepalives (0 to turn off). The default value is 0, which is changed to 60.

Putty settings

Putty

Enable putty keepalive

Putty-> Connection-> Seconds between keepalives (0 to turn off). The default value is 0, which is changed to 60.

Ii. Change the configuration file/etc/ssh/sshd_config of the ssh server

ClientAliveInterval specifies the time interval for the server to request messages from the client. The default value is 0, and no message is sent. ClientAliveInterval 60 indicates that the request is sent once every minute, and then the client responds, so that the persistent connection is maintained. The strange thing here is that the client does not actively initiate a request to maintain the connection (such as FTerm and CTerm), but the server needs to take the initiative first.

In addition, for ClientAliveCountMax, use the default value 3. ClientAliveCountMax indicates that after the server sends a request, the client automatically disconnects when the number of times the client does not respond to a certain value. Normally, the client does not respond.

After the server is changed, remember to save and remember to restart the ssh service.

After the modification, the above methods can keep the ssh connection in alive State and will not be forced to be disconnected by the server due to no operation.