Joe McEntire | Debian Security iptables firewall @JoeMcEntire | Uploaded October 2014 | Updated October 2024, 1 week ago.
This video will show you how to setup and manage an iptables firewall on Debian 7 Wheezy GNU/Linux.

Here is an excellent write up on iptables if you're interested in additional reading: http://www.cyberciti.biz/tips/linux-iptables-examples.html