If you google for POD or Packet Of Death you'll see there have been various schemes to implement a message that will instantly disconnect a user from whatever network resource they are using (or abusing) - I think there might even be a RADIUS RFC on it.
ACS doesnt implement any such back end features though.
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...