Iptables CheatSheet

Basic Commands

$ sudo iptables -L -v -n --line-numbers # list chains
$ sudo iptables -D INPUT 2 # delete line 2 from INPOUT chain
$ sudo iptables -D INPUT -s 202.54.1.1 -j DROP # find source IP 202.54.1.1 and delete from rule

$ sudo iptables -F # -F : Deleting (flushing) all the rules.
$ sudo iptables -X # -X : Delete chain.
$ sudo iptables -t nat -F # -t table_name : Select table (called nat or mangle) and delete/flush rules.
$ sudo iptables -t nat -X
$ sudo iptables -t mangle -F
$ sudo iptables -t mangle -X
$ sudo iptables -P INPUT ACCEPT # -P : Set the default policy (such as DROP, REJECT, or ACCEPT).
$ sudo iptables -P OUTPUT ACCEPT
$ sudo iptables -P FORWARD ACCEPT


$ sudo iptables -I INPUT 1 -s 10.90.135.135 -m state --state NEW -p udp --dport 161 -j ACCEPT # Prepend
$ sudo iptables -A INPUT -s 10.90.135.135 -m state --state NEW -p udp --dport 161 -j ACCEPT   # Append
$ sudo iptables -A INPUT -m state --state NEW -p udp --dport 161 -j LOG
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