The description of your signature message is âTriggers on a DNS request for all records. This signature indicates that your network may be under reconnaissanceâ. Where "reconnaissance" means investigation, inspection, exploration, or survey so in my mind it might be an attack and not just an informative message.This message is generally associated to network scans based on dns query sent to your network. As per the below URL, this message is informative and does not suggest an attack on the network.
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...