WatchGuard Firebox System 7.0 User Guide

CHAPTER 7Configuring NetworkAddress TranslationNetwork address translation (NAT) protects your networkby hiding its internal structure. It also providesan effective way to conserve public IP addresses whenthe number of addresses is limited.At its most basic level, NAT translates the address of apacket from one value to another. The “type” of NATperformed refers to the method of translation:Dynamic NATAlso called IP masquerading or port addresstranslation. The Firebox either globally, or on aservice-by-service basis, applies its public IPaddress to outgoing packets instead of usingthe IP address of the session behind theFirebox.Static NATAlso called port forwarding. Static NAT workson a port-to-host basis. Incoming packets fromthe external network destined for a specificpublic address and port are remapped to anaddress and port behind the firewall. Youmust configure each service separately forUser Guide 101