tldr/pages/linux/iptables.md

iptables

Program that allows configuration of tables, chains and rules provided by the Linux kernel firewall.

• See chains and rules for specific table:

sudo iptables -t {{table_name}} -vnL

• Set chain policy rule:

sudo iptables -P {{chain}} {{rule}}

• Append rule to chain policy for IP:

sudo iptables -A {{chain}} -s {{ip}} -j {{rule}}

• Append rule to chain policy for IP considering protocol and port:

sudo iptables -A {{chain}} -s {{ip}} -p {{protocol}} --dport {{port}} -j {{rule}}

• Delete chain rule:

sudo iptables -D {{chain}} {{rule_line_number}}

• Save iptables configuration:

sudo iptables-save > {{path/to/iptables_file}}