Configuring Network Address Translation: Getting Started
Document ID: 13772

Contents
Introduction Prerequisites Requirements Components Used Conventions Quick Start Steps for Configuring and Deploying NAT Defining NAT Inside and Outside Interfaces Example: Allowing Internal Users to Access the Internet Configuring NAT to Allow Internal Users to Access the Internet Configuring NAT to Allow Internal Users to Access the Internet Using Overloading Example: Allowing the Internet to Access Internal Devices Configuring NAT to Allow the Internet to Access Internal Devices Example: Redirecting TCP Traffic to Another TCP Port or Address Configuring NAT to Redirect TCP Traffic to Another TCP Port or Address Example: Using NAT During a Network Transition Configuring NAT for Use During a Network Transition Example: Using NAT in Overlapping Networks Difference between One−to−One Mapping and Many−to−Many Verifying NAT Operation Conclusion Related Information

Introduction
This document explains configuring Network Address Translation (NAT) on a Cisco router for use in common network scenarios. The target audience of this document is first time NAT users. Note: In this document, when the internet, or an internet device is referred to, it means a device on any external network.

Prerequisites
Requirements
This document requires a basic knowledge of the terms used in connection with NAT. Some of the definitions can be found in NAT: Local and Global Definitions.

Components Used
The information in this document is based on these software and hardware versions: • Cisco 2500 Series Routers • Cisco IOS® Software Release 12.2 (10b)

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact