openssh

#ubuntu

[ssh-install]
sudo apt-get install openssh-server
[ssh-check]
ps aux | grep ssh
[ssh-config]
sudo vim /etc/ssh/sshd_config
[ssh-root_login]
#PermitRootLogin Yes 
>>
PermitRootLogin no
[ssh-port]
# What ports, IPs and protocols we listen for
Port 22
[check-in_using_port]
sudo less /etc/services
[ssh-ip_allow+deny]
sudo vim /etc/hosts.allow
sudo vim /etc/hosts.deny
[ssh-ip_allow_ex]
sshd:xxx.xxx.xxx.xxx :allow
[ssh-ip_deny_ex]
sshd:all:deny
[ssh-restart]
sudo /etc/init.d/ssh stop
sudo /etc/init.d/ssh start