iptables-&iptables-version; The next part of this chapter deals with firewalling. The principle firewalling tool for Linux, as of the 2.4 kernel series, is iptables. It replaces ipchains from the 2.2 series and ipfwadm from the 2.0 series. You will need to install iptables if you intend on using any form of firewalling. &iptables-intro; &iptables-inst; &iptables-exp; &iptables-desc;