Linksys AG041 User manual

A Division of Cisco Systems, Inc.
®
Model No.
WIRED User Guide
with 4-Port Switch
AG041 (EU)
ADSL Gateway

ADSL Gateway with 4-Port Switch
Copyright and Trademarks
Specifications are subject to change without notice. Linksys is a registered trademark or trademark of Cisco
Systems, Inc. and/or its affiliates in the U.S. and certain other countries. Copyright © 2004 Cisco Systems, Inc. All
rights reserved. Other brands and product names are trademarks or registered trademarks of their respective
holders.
How to Use this Guide
Your Guide to the ADSL Gateway has been designed to make understanding networking with the Gateway easier
than ever. Look for the following items when reading this User Guide:
In addition to these symbols, there are definitions for technical terms that are presented like this:
Also, each figure (diagram, screenshot, or other image) is provided with a figure number and description, like
this:
Figure numbers and descriptions can also be found in the "List of Figures" section in the “Table of Contents”.
AG041-UG-EU-40429NC BW
This exclamation point means there is a Caution or
Warning and is something that could damage your
property or the Gateway.
word: definition.
This checkmark means there is a Note of interest and
is something you should pay special attention to while
using the Gateway.
This question mark provides you with a reminder about
something you might need to do while using the Gateway.
Figure 0-1: Sample Figure Description

ADSL Gateway with 4-Port Switch
Table of Contents
Chapter 1: Introduction1
Welcome 1
What’s in this Guide? 2
Chapter 2: Planning your Network 4
The Gateway’s Functions 4
IP Addresses 4
What is a VPN? 5
Why do I need a VPN? 6
Chapter 3: Getting to Know the ADSL Gateway 8
The Back Panel 8
The Front Panel 9
Chapter 4: Connecting the ADSL Gateway 10
Overview 10
Connecting to a Computer 10
Chapter 5: Configuring the ADSL Gateway 12
Overview 12
How to Access the Web-based Utility 13
The Setup Tab 14
The Security Tab 22
The Access Restrictions Tab 27
The Applications and Gaming Tab 29
The Administration Tab 32
The Status Tab 37
Appendix A: Troubleshooting 39
Common Problems and Solutions 39
Frequently Asked Questions 47
Appendix B: Configuring IPSec between a Windows 2000
or XP Computer and the Gateway 51
Introduction 51
Environment 51
How to Establish a Secure IPSec Tunnel 52
Appendix C: Finding the MAC Address and IP Address for Your Ethernet Adapter 62

ADSL Gateway with 4-Port Switch
Windows 98 or Me Instructions 62
Windows 2000 or XP Instructions 63
Appendix D: Upgrading Firmware 64
Appendix E: Windows Help 65
Appendix F: Glossary 66
Appendix G: Specifications 70
Appendix H: Warranty Information 71
Appendix I: Regulatory Information 72
Appendix J: Contact Information 73

ADSL Gateway with 4-Port Switch
List of Figures
Figure 2-1: A Network with the Gateway 4
Figure 2-2: Computer-to-VPN Gateway 6
Figure 2-3: VPN Gateway-to-VPN Gateway 7
Figure 3-1: Back Panel 8
Figure 3-2: Front Panel 9
Figure 4-1: Connect your network 10
Figure 4-2: Connect your ADSL modem 10
Figure 4-3: Connect power 11
Figure 5-1: Password Screen 14
Figure 5-2: Basic Setup Tab 14
Figure 5-3: Internet Setup - Dynamic IP 15
Figure 5-4: Internet Setup - Static IP 15
Figure 5-5: Internet Setup - RFC 1483 Routed 16
Figure 5-6: Internet Setup - RFC 2516 PPPoE 16
Figure 5-7: Internet Setup - RFC 2364 PPPoA 17
Figure 5-8: Internet Setup - Bridged Mode Only 17
Figure 5-9: Setup Tab - Optional Settings 18
Figure 5-10: Setup Tab - DDNS 19
Figure 5-11: Setup Tab - Advanced Routing 20
Figure 5-12: Routing Table 21
Figure 5-13: Security Tab - Firewall 22
Figure 5-14: Security Tab - VPN 23
Figure 5-15: VPN with Manual Key Management 24
Figure 5-16: Advanced IPSec VPN Tunnel Setup 25
Figure 5-17: Access Restrictions - Internet Access 27
Figure 5-18: Internet Policy Summary 27
Figure 5-19: List of PCs 28
Figure 5-20: Port Services 28
Figure 5-21: Applications & Gaming - Single Port Forwarding 29
Figure 5-22: Applications & Gaming - Port Range Forwarding 30

ADSL Gateway with 4-Port Switch
Figure 5-23: Applications & Gaming - Port Triggering 30
Figure 5-24: Applications & Gaming - DMZ 31
Figure 5-25: Administration tab - Management 32
Figure 5-26: Administration tab - Reporting 34
Figure 5-27: Adminstration tab - Diagnostics 35
Figure 5-28: Administration tab - Factory Defaults 35
Figure 5-29: Administration tab - Firmware Upgrade 36
Figure 5-30: Status tab - Gateway 37
Figure 5-31: Status tab - Local Network 38
Figure 5-32: DHCP Active IP Table 38
Figure 5-33: Status tab - DSL Connection 38
Figure B-1: Local Security Screen 52
Figure B-2: Rules Tab 52
Figure B-3: IP Filter List Tab 52
Figure B-4: IP Filter LIst 53
Figure B-5: Filters Properties 53
Figure B-6: New Rule Properties 53
Figure B-7: IP Filter List 54
Figure B-8: Filters Properties 54
Figure B-9: New Rule Properties 54
Figure B-10: IP Filter List Tab 55
Figure B-11: Filter Acton Tab 55
Figure B-12: Security Methods Tab 55
Figure B-13: Authentication Methods 56
Figure B-14: Preshared Key 56
Figure B-15: New Preshared Key 56
Figure B-16: Tunnel Setting Tab 57
Figure B-17: Connection Type Tab 57
Figure B-18: Properties Screen 57
Figure B-19: IP Filter List Tab 58
Figure B-20: Filter Action Tab 58
Figure B-21: Authentication Methods Tab 58
Figure B-22: Preshared Key 59

ADSL Gateway with 4-Port Switch
Figure B-23: New Preshared Key 59
Figure B-24: Tunnel Setting Tab 59
Figure B-25: Connection Type 60
Figure B-26: Rules 60
Figure B-27: Local Computer 60
Figure B-28: VPN Tab 61
Figure C-1: IP Configuration Screen 62
Figure C-2: MAC Address/Adapter Address 62
Figure C-3: MAC Address/Physical Address 63
Figure D-1: Upgrade Firmware 64

1
Chapter 1: Introduction
Welcome
ADSL Gateway with 4-Port Switch
Chapter 1: Introduction
Welcome
Thank you for choosing the ADSL Gateway with 4-Port Switch. This Gateway will allow your computers to share a
high-speed Internet connection with its built-in modem, as well as share resources, including files and printers,
through its built-in Switch. Because the modem, router, and switch are all built-in, creating a network is easier
than ever.
Put simply, networks are useful tools for sharing computer resources. You can access one printer from different
computers and access data located on another computer’s hard drive. Networks are even used for playing
multiplayer video games. So, networks not only are useful in homes and offices, but also can be fun.
To create your network, install and set up the Gateway. To guide you through the process, use the instructions in
the Quick Installation or the directions in this User Guide to help you. These instructions should be all you need to
get the most out of the Gateway and, for more advanced users, this User Guide shows you many of the Gateway’s
Advanced uses as well. This User Guide also contains appendices to answer further questions and a Glossary if
you’re unfamiliar with terms. Basically, if you have a question about the Gateway, you should find the answers
within.
network: a series of computers or devices
connected for the purpose of data sharing,
storage, and/or transmission between users
port: the connection point on a computer or networking
device used for plugging in cables or adapters
router: a networking device that connects
multiple networks together

2
Chapter 1: Introduction
What’s in this Guide?
ADSL Gateway with 4-Port Switch
What’s in this Guide?
This user guide covers the steps for setting up and using the ADSL Gateway.
• Chapter 1: Introduction
This chapter describes the ADSL Gateway and its documentation.
• Chapter 2: Planning your Network
This chapter describes the basics of networking.
• Chapter 3: Getting to Know the ADSL Gateway
This chapter describes the physical features of the Gateway.
• Chapter 4: Connecting the ADSL Gateway
This chapter instructs you on how to connect the Gateway to your network.
• Chapter 5: Configuring the Gateway
This chapter explains how to use the Web-Based Utility to configure the settings on the Gateway.
• Appendix A: Troubleshooting
This appendix describes some problems and solutions, as well as frequently asked questions, regarding
installation and use of the ADSL Gateway.
• Appendix B: Configuring IPSec between a Windows 2000 Computer and the Gateway
This appendix instructs you on how to establish a secure IPSec tunnel using preshared keys to join a private
network inside the VPN Gateway and a Windows 2000 or XP computer.
• Appendix C: Finding the MAC Address and IP Address for your Ethernet Adapter.
This appendix describes how to find the MAC address for your computer’s Ethenet adapter so you can use the
MAC filtering and/or MAC address cloning feature of the Gateway.
• Appendix D: Upgrading Firmware
This appendix instructs you on how to upgrade the firmware on your Gateway if you should need to do so.
• Appendix E: Windows Help
This appendix describes how you can use Windows Help for instructions about networking, such as installing
the TCP/IP protocol.
• Appendix F: Glossary
This appendix gives a brief glossary of terms frequently used in networking.

3
Chapter 1: Introduction
What’s in this Guide?
ADSL Gateway with 4-Port Switch
• Appendix G: Specifications
This appendix provides the technical specifications for the Gateway.
• Appendix H: Warranty Information
This appendix supplies the warranty information for the Gateway.
• Appendix I: Regulatory Information
This appendix supplies the regulatory information regarding the Gateway.
• Appendix J: Contact Information
This appendix provides contact information for a variety of Linksys resources, including Technical Support.