If you have ever been confused by iptables now is your chance to learn its dark magic. Iptables doesn’t just work on the Network layer in TCP/IP stack, but can also be used to filter data link and transport layer traffic. Iptables consists of tables, which consists of chains, which is further comprised of rules. We will provide a high level over view of how iptables works in the Linux kernel and go over its syntax to write rules to filter and block traffic. This will consist of an 1 hour lecture followed by a lab. Please bring a virtual machine with Linux Centos or Ubuntu installed.