How to ban an IP with iptables?

In this tutorial, we will see how to ban an IP address on your VPS server under Linux. We will use the firewall iptables.

Install iptables

To install iptables, let's use the package manager. You must have administrator access.

Installing iptables on Ubuntu

To install iptables on Ubuntu:

sudo apt-get install iptables

Installing iptables on Debian

To install iptables on Debian:

apt-get install iptables

Installing iptables on CentOS

To install iptables on CentOS:

sudo yum install iptables

Displays the list of IP bans

To display the list of banned IPs on iptables:

iptables -L

Ban an IP address on iptables

In the case of an IP address that attacks a site and/or a server, here is the command:

iptables -A INPUT -s XXX.XXX.XXX.XXX -j DROP

Don't forget to replace the IP address with the one you want to block.

You can verify that the address is banned with iptables -L.

Deban an ip address on iptables

To unban an IP address, use the DROP command:

iptables -D INPUT -s XXX.XXX.XXX.XXX -j DROP