I went with Flexvpn on a 4431 ISR to setup Remote Access VPN for my company's remote users. Worked much better than the older solution. However, with cellular providers moving to IPv6, we've started having issues.
Initially, cellular clients on IPv6 networks won't connect to our headend. The connection requests would just time out without even getting to the login prompt. I enabled IKEv2 fragmentation on our headend and it seemed like it fixed the issue. Remote users were able to get the credential prompt and login to the VPN. However, there is no traffic flowing for those clients. The clients(running latest version of the AnyConnect mobile client for Android and iOS) send packets but receive nothing in return. I ran captures on the inside interface of the headend and I can see ecmp requests and replies, can't trace where the replies get timed out.
Opened a case with TAC over a month ago and they have had no luck with it. If anyone has ever run into something like this, please advise.
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...