Cisco IDS does not currently have the ability to identify packets with a specific TCP Window Size of 55808. However, based on the research presented, it is possible to create a custom signature / filter combination to catch the current Stumbler implementations.
1) Create a custom ATOMIC.TCP signature with the following parameters.
Mask SYN | FIN | URG | PSH | ACK | RST
2) Create a filter for the custom alarm you created to catch for the destination
IP address "188.8.131.52". Please consult the Cisco IDS documentation for directions on adding a signature filture.
We are looking into adding an enhancement to Cisco IDS to allow for specific TCP Window Sizes to be identified.
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...