Configuring Nat; Overview - Juniper IP SERVICES - CONFIGURATION GUIDE V 11.1.X Configuration Manual

Chapter 2

Configuring NAT

Overview

This chapter describes how to configure Network Address Translation (NAT) on your
ERX router; it contains the following sections:
Overview on page 63
Platform Considerations on page 64
References on page 64
NAT Configurations on page 65
Network and Address Terms on page 66
Understanding Address Translation on page 67
Address Assignment Methods on page 68
Order of Operations on page 69
PPTP and GRE Tunneling Through NAT on page 70
Packet Discard Rules on page 70
Before You Begin on page 70
Configuring a NAT License on page 71
Limiting Translation Entries on page 71
Specifying Inside and Outside Interfaces on page 71
Defining Static Address Translations on page 72
Defining Dynamic Translations on page 74
Clearing Dynamic Translations on page 79
NAT Configuration Examples on page 79
Tunnel Configuration Through NAT Examples on page 86
GRE Flows Through NAT on page 88
Monitoring NAT on page 88
The Internet faces the challenges of conserving IP address space while continuing
to provide scalability in routing. Network Address Translation (NAT) helps address
these challenges by allowing the conservation of registered IP addresses within private
networks and simplifying IP addressing management tasks through a form of
transparent routing.
63
Overview