Iptables (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. iptables is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall and the chains and rules it stores. Different kernel modules and programs are currently used for different protocols; iptables applies to IPv4, ip6tables to IPv6, arptables to ARP, and ebtables to Ethernet frames. iptables requires elevated privileges to operate and must be executed by user root, otherwise it fails to function. On most Linux systems, iptables is installed as /usr/sbin/iptables and documented in its man page, which can be opened using man iptables when installed. It may also be found in /sbin/iptables, but since iptables is more like a service rather than an "essential binary," the preferred location remains /usr/sbin.