Blocking a port using the Custom Rules

You can add custom rules to block an IP port from generic access and grant only to a specific set of IP addresses

Let's make an example. if you want to block ssh port 22 from any access except from IP 192.168.1.100, you can enter the following data

 -s 192.168.1.100/32 -p tcp --dport 22 -j ACCEPT
 -p tcp --dport 22 -j DROP

Please take in mind all IP in the "Always allowed list" will be always allowed, regardless what has been entered in the Custom Rules field