Use tools such as XShell or Putty to operate the remote link server system, and find that the connection is not available.
First understand what SSH is: SSH is the abbreviation of Secure Shell, which is a security protocol based on the application layer and the transport layer. SSH is a protocol designed to provide security for remote login sessions and other network services, and is commonly used for remote logins. That is, SSH is used to remotely operate a server on a Linux system.
Installation of SSH
- Check if SSH is installed
Enter the command:
ssh logcalhost
If the following message is displayed, it is not installed:
ssh: connect to host localhost port 22: Connection refused
- Install SSH
Enter the command:
sudo apt-get install openssh-server
- Check if SSH is installed successfully
Enter the command:
sudo ps -e | grep ssh
The following message is displayed, indicating success:
2895 ？ 00:00:00 sshd
- Query the current status of SSH
Enter the command:
sudo service ssh status
Output SSH stop/waiting SSH stopped
Output SSH start/running, process 3090 is running
- Start SSH
Enter the command:
sudo service ssh start
A display of start: Job is already running: SSH indicates that SSH is running
- Stop SSH
Enter the command:
sudo service ssh stop
- Restart SSH
Enter the command:
sudo service ssh restart
- Uninstall SSH
Enter the command:
sudo apt-get autoremove –purge openssh-server
Once successfully installed and launched, the server can be operated remotely using tools such as XShell or Putty
