AFAIK, I have not specified what IP addresses that someone can telnet from to log onto the PIX. I have tried the following, but I'm sure I haven't provided the correct statements:
aaa authentication include telnet inside 192.168.0.0 255.255.0.0 Admin-FW
... and I get a Username / Password prompt on the PIX but it keeps asking for a username and password. I know my TACACS account is fine since I can log onto routers with the same details as what I am using to authenticate to the PIX.
I also ran a debug on the PIX when I was trying to authenticate. The output is attached.
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...