iptables is a command for controlling how IPv4 traffic is processed by the Linux kernel firewall (netfilter). Common reasons for using it are to block unauthorised traffic or to enable Network Address Translation (NAT).
- Block unsolicited inbound network traffic using iptables
- Implement port knocking using iptables
- Limit the rate of inbound TCP connections using iptables
- Make the configuration of iptables persistent (Debian)
- Share an IP address between clients using iptables
- Share an IP address between servers using iptables