Configuring SSH

1: Search if the package is laready installed.
     #rpm -qa | grep ssh

2:   #yum search ssh
3:   #yum install openssh-server
4:  Make sure you flush iptables before setting any new iptables rule
5: Don't flush your iptables in the middle/end else all your set iptables
    #iptables -F
    #service iptables save
    #service iptables restart

Setting IPTABLE Rules

6: Clients within remote.test should not have SSH access to your system

  #iptables -I INPUT -s <remote.test n/w address> -p tcp --dport 22 j REJECT

7: Only 192.168.0.1/255.255.255.0 should have SSH access

  #iptables -I INPUT ! -s 192.168.0.1/255.255.255.0 -p tcp --dport 22 -j REJECT

8: 192.168.0.1/255.255.255.0 should have SSH access

  #iptables -I INPUT -s 192.168.0.1/255.255.255.0 -p tcp --dport 22 -j ACCEPT