How to Whitelist/Allow Incoming connection from an IP address
Login into your Linux server via SSH as ‘root’ user
Run the command
iptables -A INPUT -s IPADDRESS -j ACCEPT
to whitelist/Allow the IP address
Save the Iptables rule by running the command
service iptables save
You must replace “IPADDRESS” in the Step 2 with the IP address you wish to whitelist.
How to Whitelist/Allow Outgoing connection to an IP address
Login to the Linux server via SSH as ‘root’ user
Run the command
iptables -A OUTPUT -d IPADDRESS -j ACCEPT
to whitelist Outgoing connections
Run the command
service iptables save
to save the IPtables rules.