Common iptables commands

A few years ago I wrote a iptables tutorial explaining the basics of the topic. This post is just a small cheat sheet of most simple and effective commands that I end up using very frequently. I am assuming that we are operating for IP 1.1.1.1 and using INPUT chain of the iptables.

1. Block an IP
   iptables -A INPUT -s 1.1.1.1 -j DROP
2. Block an IP range
   iptables -A INPUT -s 1.1.1.1/24 -j DROP
3. List current rule set
   iptables --list
4. List current rules set with numbers
   iptables --line-numbers --list
5. Delete a rule by rule
   iptables -D INPUT -s 1.1.1.1 -j DROP
6. Delete a rule by number
   iptables -D INPUT 7
7. Save iptables rules to a file
   iptables-save > iptables.dat
8. Load iptables rules from a file
   iptables-restore < iptables.dat