Sounds like your not talking web filtering - rather more like port filtering. You can use either some outbound commands or access-list commands to block those ports to the outside interface. Its pretty easy to find out what ports they run on on the internet. In fact, you might even want to only allow port 80 outbound - restricting all but web traffic - not sure how evil you might be! :)
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...
[toc:faq]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 and UDP are I...