Netfilter and IPTables
The Linux kernel features a powerful networking subsystem called Netfilter. The Netfilter subsystem provides stateful or stateless packet filtering as well as NAT and IP masquerading services. Netfilter also has the ability to mangle IP header information for advanced routing and connection state management. Netfilter is controlled using the The power and flexibility of Netfilter is implemented using the A similar syntax does not mean similar implementation, however. By contrast, This section provides an overview of iptables tool.
IPTables Overview
iptables administration tool, a command line tool similar in syntax to its predecessor, ipchains.
ipchains requires intricate rule sets for: filtering source paths; filtering destination paths; and filtering both source and destination connection ports.
iptables uses the Netfilter subsystem to enhance network connection, inspection, and processing. iptables features advanced logging, pre- and post-routing actions, network address translation, and port forwarding, all in one command line interface.
iptables. For more detailed information, refer to "IPTables".