Basically, you run an instance of the BIND DNS server, and the script automatically keeps it up-to-date with known-malicious domain names from a bunch of different sources. It does not do site categorizations, though, so you can't permit/deny inappropriate sites (e.g. porn) that isn't malicious.
Even if you're not going to run the full instance of BIND, the script itself is a pretty interesting.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...