SSH server, you can access the remote server via SSH protocol instead of Telnet and FTP. However, Ubuntu defaults to not enable root users and does not allow root login. So you need to enable the root user first
Enable root User: sudo passwd root//Change password is enabled.
To install OpenSSH server:
1. Install OpenSSH server using the APT command
$ sudo apt-get install Openssh-server
2. OpenSSH server can be configured
$ sudo vi/etc/ssh/sshd_config
Find Permitrootlogin No Line and change to permitrootlogin Yes
3. Restart OpenSSH server
$ sudo service ssh restart
4. If the client is Ubuntu, you have installed the SSH client, you can use the following command to connect to the remote server.
$ ssh xxx.xxx.xxx.xxx
If it is a Windows system, you can connect remotely using SSH software such as SSH Secure shell.
Allow root user ssh remote login under Ubuntu