Ubuntu does not allow root to log in to xftp
Modify the / etc / SSH / sshd_config file, but only if openssh is installed. If the file does not exist, check whether openssh is installed.
If not, install with the following command:
sudo apt-get install openssh-server
Then check whether SSH is started by the following command:
ps -e | grep ssh
If only SSH agent indicates that it has not been started, you need to
Authentication: LoginGraceTime 120 PermitRootLogin prohibit-password trictModes yes
Change to the following:
Authentication: LoginGraceTime 120 PermitRootLogin yes StrictModes yes
Then exit the VIM edit and enter the command / etc / init.d/ssh restart
Just restart the SSH service.