Check the event log on the server where you have the Acs software installed. Under the security section of the event log it should show the failed attempts. We had a similar problem and the ACS software was trying to authenticate the users to the wrong domain. I know that the ACS software should check all domains listed but it still was not working. The only fix that we have foung is to have the users precede their username with their domains. If you do find a fix for this problem please let me know as well.
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...