As long as both the sides support the standards, things must work out fine. Check your IKE policies on both the sides to exact match for at least one policy on both sides. If there are not matching policies on both sides, IKE SAs will not be established. Also check the IPSEC parameters such as transform-sets, crypto-maps, interesting traffic, PFS settings etc. to match on both ends. Also check if the UDP/500 (for IKE) and IP/50(for ESP) or IP/51(for AH) traffic can pass freely between the two peers. Most of the time these are the issues that prevent the tunnel to come up.
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...