we have a ASA5500 with 3 interfaces : outside, dmz, inside
we have a number of static nats translating a given public IP to a dmz servers and that all works fine. However for testing purposes, we need to be able to access the public IP from the inside interface.
You need both of them for proper communication between the interfaces i.e. inside and DMZ. As Marcin said, one will ensure that when your inside hosts try to access the public IP of the DMZ server, it gets translated to corresponding DMZ IP. Other one is needed to satisfy the firewall requirement i.e. NAT rules are needed when you go from higher security interface (inside) to a lower security interface (DMZ).
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...