This article draws a lot from the article: http://www.cnblogs.com/nodot/archive/2011/06/10/2077595.html
thanks
1. Install the login server
sudo apt-get install openssh-server
2. Configure the port
sudo gedit /etc/ssh/sshd_config
Port 22 is the place to modify the port, and it can be not modified by default. I don't know about other configurations. .
3. After configuration, restart the SSH server
sudo /etc/init.d/ssh start or service ssh start