SSH

For Ubuntu, how to start/stop/status SSH service:

# service ssh stop
# service ssh start
# service ssh restart
# service ssh status
OR
# /etc/init.d/ssh stop
# /etc/init.d/ssh start
# /etc/init.d/ssh restart
# /etc/init.d/ssh status

Resources:

http://www.cyberciti.biz/faq/how-to-installing-and-using-ssh-client-server-in-linux/

http://www.cyberciti.biz/faq/debian-linux-install-openssh-sshd-server/