WESM zl Management and Configuration Guide WT.01.28 and greater

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8
Configuring Network Address Translation (NAT)
Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Translating Between an Inside and an Outside Network . . . . . . . . . . . . . . 8-3
Local and Global Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
NAT Implementation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Dynamic, or Many-to-One, NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Dynamic NAT for Wireless Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Dynamic NAT for Wired Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7
Port Address Translation for Dynamic NAT . . . . . . . . . . . . . . . . . . . . 8-8
Static, or One-to-One, NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
Static NAT on Destination Addresses . . . . . . . . . . . . . . . . . . . . . . . . . 8-9
Using Port Forwarding with Static Destination NAT . . . . . . . . . . . . 8-10
Static NAT on Source Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Understanding Local and Global Addresses . . . . . . . . . . . . . . . . . . . . . . . 8-12
Planning the NAT Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15
Consider Your Company’s Requirements for NAT . . . . . . . . . . . . . . . . . 8-15
Record Necessary IP Addresses and Select the NAT
Implementation Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17
Planning the Configuration for Dynamic NAT . . . . . . . . . . . . . . . . . 8-17
Planning the Configuration for Static NAT . . . . . . . . . . . . . . . . . . . . 8-19
Configuring Standard ACLs for Dynamic NAT . . . . . . . . . . . . . . . . . . . . . . . . 8-22
Configuring NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24
Defining Interfaces as Outside or Inside . . . . . . . . . . . . . . . . . . . . . . . . . . 8-24
Configuring Dynamic NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26
Configuring Static Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-29
Configuring Static Source NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-30
Configuring Static Destination NAT . . . . . . . . . . . . . . . . . . . . . . . . . 8-33
Viewing NAT Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-38