How to Block an IPaddress on CentOS, Fedora and Redhat Linux Server

How to Block an IPaddress on CentOS, Fedora and Redhat Linux Server

 
You must have server root access to blacklist / Block the IPaddress on Linux server. Steps to drop Incoming connection from an IPaddress to the Linux server is given below :
 

How to Drop / Block Incoming connection from an IP address on a linux server

 
Step 1: Log into your Linux server via SSH as ‘root’ user

Step 2: Run the command “iptables -A INPUT -s IPADDRESS -j DROP” to block the IP address

Step 3: Run the command “service iptables save” to save the IPtables rules

‘IPADDRESS’ in Step 2 should be replaced with the IP address you wish to Block.
 

How to Drop / Block Outgoing connection to a specific IP address

 
Step 1: Log into Linux Server via SSH as ‘root’ user

Step 2: Run the command “iptables -A OUTPUT -d IPADDRESS -j DROP”

Step 3: Save the IPtables Rules by running the command “service iptables save”