Cisco realsed new feature on 12.4(4) IOS, it claims that the router can classify the Skype traffic by using the NBAR with Skype classification feature. I checked it but it seems that the router can classify the traffic as well as you permit it, but when I droped it with the drop command it seems that IOS can no loger catch Skype. Any comment?
I have read that if Skype can't get though one way it morphs and resorts to other ports. That means the only way to reliably catch that traffic may be something with deep packet inspection like a third party traffic shapper or know enough about this undocumented protocol to know what it is going to do. NetworkWorld, Dec. 9, Volume 15, No. 20, headlines: "Skype poses risks".
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...