Looking at the errors, you can see that received packet from SonicWall was invalid thus parameter negotiation failed between the VPN peers. Perhaps simultaneous logs from SonicWall might be able to tell what caused this event. Usually with 3rdp party appliances , it is relevant to make sure that peer ID and peer IP are configured in the same format(Using IP addressing in both the cases rather hostname).
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...