# 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}}`