Workshop about netfilter/iptables firewall administration Target audience: System and Network Administrators Prerequirements: Advanced knowledge about the TCP/IP protocol suite, general GNU/Linux system adminstration skills. Goal: To give an in-depth introduction into the netfilter/iptables subsystem of the Linux kernel. Given the information in this workshop, the audience should be able to configure and use netfilter/iptables in an effective way. Table of contents: - The history of the linux packet filter (ipfwadm, ipchains, iptables) - netfilter: the hooks - iptables: the packet matching system on top of netfilter - general structure - available targets - available matches - iptable_filter: Packet filtering - iptable_mangle: Packet mangling - ip_conntrack: Connection tracking on top of netfilter - iptable_nat: Combining netfilter, iptables and ip_conntrack - Practical examples of typical firewall rulesets - The 10 commandments of how to break your network (the "don't do" part) - Lots of time for questions & anwers