Iptables command - DD-WRT Wiki
https://wiki.dd-wrt.com/wiki/index.php/IptablesIptables command. Iptables is a powerful administration tool for IPv4 packet filtering and NAT. It is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel. Iptables commands can be entered by command line interface, and/or saved as a Firewall script in the dd-wrt Administration panel.