Check the environment
#sudo apt-get update
1) Determine whether the ssh service is installed in Ubuntu:
#ps -e | grep ssh
If the service has been started, you can see "sshd",
(2) To install the ssh service, enter the command:
#sudo apt-get install openssh-server
(3) Start the service:
#/etc/init.d/ssh start
Enter the ubuntu desktop, find "desktop sharing" in the dash menu and open it.
Check "Allow others to view your desktop"