Suppose Device A wants to see if it can reach Device B. Device A begins the test process by sending an ICMPv4 Echo message to B. Device B, when it receives the Echo, responds back to Device A with an Echo Reply message. When Device A receives this message, it knows that it is able to communicate (both send and receive) successfully with Device B.
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...