To block an individual IP address from accessing your Linux server, you can use the following iptables command:

iptables -A INPUT -s IPADDR -j DROP

Simply replace IPADDR with the IP you want to drop all packets from.

Block ranges of IP’s

Here is an example of a range block:

iptables -A INPUT -s 192.168.0.1/24 -j DROP

This would block 192.168.0.1-255

Unblock the IP

Simply change “DROP” in the commands above to “ACCEPT”.