Juniper JUNOSE 11.2.X IP SERVICES, Configuration Manual

Page: 87 / 356

CHAPTER 2
Configuring NAT
This chapter describes how to configure Network Address Translation (NAT) on your
ERX router; it contains the following sections:
• Overview on page 61
• Platform Considerations on page 62
•
References on page 62
•
NAT Configurations on page 63
• Network and Address Terms on page 64
• Understanding Address Translation on page 65
•
Address Assignment Methods on page 66
•
Order of Operations on page 66
• PPTP and GRE Tunneling Through NAT on page 67
• Packet Discard Rules on page 68
•
Before You Begin on page 68
•
Configuring a NAT License on page 68
• Limiting Translation Entries on page 69
• Specifying Inside and Outside Interfaces on page 69
•
Defining Static Address Translations on page 69
•
Defining Dynamic Translations on page 71
• Clearing Dynamic Translations on page 76
• NAT Configuration Examples on page 76
•
Tunnel Configuration Through NAT Examples on page 83
•
GRE Flows Through NAT on page 84
• Monitoring NAT on page 84
Overview
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 .
61 Copyright © 2010, Juniper Networks, Inc.