Cisco's vpn client can tunnel data in udp and tcp encapsulations. Even though you can set it up to encapsulate thru tcp to port 80, this does not make it http traffic. An application level firewall will most likely drop these packets as it is not http traffic. You probably cannot make your setup work without having admin control of the MS proxy server, if it is possible at all.
Thus the only way to let outsourced employees use the VPn client is to let the customer open 2 ports on his firewall and allow the traffic from the users PC --> This is a great impact because these PC's need a static ip address and the customer needs to enable ports udp 500 and ( in my example port tcp 80 ) the payload port.
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...