The SecureCRT is connected to the server and is timed out and disconnected.

When SecureCRT connects to the server and times out and is disconnected, the reason is that there are routers, firewalls, and idle connections between the client and the server beyond the specified time for security purposes. Or the server is set to disconnect idle connections. Solution: since idle connections will be disconnected, we should "busy" the connection between the client and the server. Method 1: starting from the server side, modify the ClientAliveInterval 300 (default: 0) parameter in the/etc/ssh/sshd_config configuration file. This parameter means that the server sends a message to the client every five minutes, method 2: Start from the client: the above configuration requires server permissions. If you do not have server permissions, you can use this method. The idea is: the client sends a message to the server to keep the connection secureCRT in the option terminal unidle to set the number of seconds to send a string or NO-OP protocol package.