Setting up a network firewall Before you read this part of the chapter, note that we assume that you have already installed iptables as described in the previous section. &postlfs-security-fw-intro; &postlfs-security-fw-disclaimer; &postlfs-security-fw-kernel; &postlfs-security-fw-writing; &postlfs-security-fw-finale; &postlfs-security-fw-extrainfo;