Summary Extensive coverage of iptables and iptables syntax, firewall policies, and attacks: SYN flood & ping flood (smurf attack). 28:13 - nano text editor usage 28:58 - How to install vi (vim) in Ubuntu 29:15 - Review of execute permissions 29:35 - Using vim to edit the firewall rules shell script 36:24 - Review of chmod command 36:53 - netstat command usage 37:11 - How to install vsftpd 37:22 - How to install openssh-server 37:48 - Running the firewall rules shell script 38:07 - Listing the active iptables firewall rules 38:45 - Testing FTP access with active firewall rules 39:33 - Testing SSH access 40:35 - Re-enabling SSH access 41:13 - Testing SSH access again (this time successful) 41:37 - Testing ping (accepted) 41:52 - Testing ping (rejected) Reference Materials Guide to Network Defense and Countermeasures - Chapter 11 (pgs. 439-444) http://www.netfilter.org/documentation/index.html - Netfilter/iptables Documentation http://www.vim.org/docs.php - Vim Documentation Additional Information Logging: http://www.thegeekstuff.com/2012/08/iptables-log-packets/