How do I restart SSH service under Linux or UNIX operating systems?
The command to restart ssh are as follows (you must login as root user):
CentOS / RHEL / Fedora / Redhat Linux Restart SSH
# /etc/init.d/sshd restart
# service sshd restart
Debian / Ubuntu Linux Restart SSH
# /etc/init.d/ssh restart
# service ssh restart
FreeBSD Restart SSH
# /etc/rc.d/sshd restart
UNIX Restart SSH
# kill -HUP `cat /var/run/sshd.pid`
Please note that the location of /var/run/sshd.pid may change. So just search a bit through /var/run/ directory.