Block Incoming Request From IP 1.2.3.4
The following command will drop any packet coming from the IP address 1.2.3.4:
# /sbin/iptables -I INPUT -s {IP-HERE} -j DROP
# /sbin/iptables -I INPUT -s 1.2.3.4 -j DROP
Finally, the last thing we need to do is save our rules so that next time we reboot our computer our rules are automatically reloaded:
# /sbin/service iptables save
Check to see if it is added:
# iptables --list -n | grep 37.233.38.46 DROP all -- 37.233.38.46 0.0.0.0/0
Other good info to check out: