The default protocol and port for PPTP is TCP/1723 and GRE, while L2TP is UDP/1701 and GRE, and inspecting PPTP on both ASA will not work if you change it to the non default port. Can you please advise which part (control or data of PPTP is changed to port 16000)? Assuming it's the control, then you would need to configure port 16000 specific to be inspected by PPTP.
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...