Linksys AG041 User Manual

A Division of Cisco Systems, Inc.

®

Model No.

WIRED

AG041 (EU)

ADSL Gateway

with 4-Port Switch

User Guide

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:

This checkmark means there is a Note of interest and
is something you should pay special attention to while
using the Gateway.

This exclamation point means there is a Caution or
Warning and is something that could damage your
property or the Gateway.

This question mark provides you with a reminder about
something you might need to do while using the Gateway.

In addition to these symbols, there are definitions for technical terms that are presented like this:

word: definition.

Also, each figure (diagram, screenshot, or other image) is provided with a figure number and description, like
this:

Figure 0-1: Sample Figure Description

Figure numbers and descriptions can also be found in the "List of Figures" section in the “Table of Contents”.

AG041-UG-EU-40429NC BW

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

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

Chapter 1: Introduction
Welcome

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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.

Chapter 1: Introduction
What’s in this Guide?

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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.

Chapter 1: Introduction
What’s in this Guide?

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ADSL Gateway with 4-Port Switch

Chapter 2: Planning your Network

The Gateway’s Functions

A Gateway is a network device that connects two networks together.

In this instance, the Gateway connects your Local Area Network (LAN), or the group of computers in your home or
office, to the Internet. The Gateway processes and regulates the data that travels between these two networks.

The Gateway’s NAT feature protects your network of computers so users on the public, Internet side cannot
“see” your computers. This is how your network remains private. The Gateway protects your network by
inspecting every packet coming in through the Internet port before delivery to the appropriate computer on your
network. The Gateway inspects Internet port services like the web server, ftp server, or other Internet
applications, and, if allowed, it will forward the packet to the appropriate computer on the LAN side.

Remember that the Gateway’s ports connect to two sides. The LAN ports connect to the LAN, and the ADSL port
connects to the Internet. The LAN ports transmit data at 10/100Mbps.

IP Addresses

What’s an IP Address?

IP stands for Internet Protocol. Every device on an IP-based network, including computers, print servers, and
Gateways, requires an IP address to identify its “location,” or address, on the network. This applies to both the
Internet and LAN connections. There are two ways of assigning an IP address to your network devices. You can
assign static IP addresses or use the Gateway to assign IP addresses dynamically.

Static IP Addresses

A static IP address is a fixed IP address that you assign manually to a computer or other device on the network.
Since a static IP address remains valid until you disable it, static IP addressing ensures that the device assigned
it will always have that same IP address until you change it. Static IP addresses must be unique and are
commonly used with network devices such as server computers or print servers.

Chapter 2: Planning your Network
The Gateway’s Functions

Figure 2-1: A Network with the Gateway

LAN: the computers and networking products that
make up your local network

FTP: a protocol used to transfer files over a TCP/IP network

NOTE: Since the Gateway is a device that connects two
networks, it needs two IP addresses—one for the LAN,
and one for the Internet. In this User Guide, you’ll see
references to the “Internet IP address” and the “LAN IP

address.”

Since the Gateway uses NAT technology, the only IP
address that can be seen from the Internet for your
network is the Gateway’s Internet IP address. However,
even this Internet IP address can be blocked, so that the
Gateway and network seem invisible to the Internet—
see the Block WAN Requests description under Security
in “Chapter 5: Configuring the ADSL Gateway.”

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ADSL Gateway with 4-Port Switch

Since you use the Gateway to share your DSL Internet connection, contact your ISP to find out if they have
assigned a static IP address to your account. If so, you will need that static IP address when configuring the
Gateway. You can get that information from your ISP.

Dynamic IP Addresses

A dynamic IP address is automatically assigned to a device on the network, such as computers and print servers.
These IP addresses are called “dynamic” because they are only temporarily assigned to the computer or device.
After a certain time period, they expire and may change. If a computer logs onto the network (or the Internet) and
its dynamic IP address has expired, the DHCP server will automatically assign it a new dynamic IP address.

DHCP (Dynamic Host Configuration Protocol) Servers

Computers and other network devices using dynamic IP addressing are assigned a new IP address by a DHCP
server. The computer or network device obtaining an IP address is called the DHCP client. DHCP frees you from
having to assign IP addresses manually every time a new user is added to your network.

A DHCP server can either be a designated computer on the network or another network device, such as the
Gateway. By default, the Gateway’s DHCP Server function is enabled.

If you already have a DHCP server running on your network, you must disable one of the two DHCP servers. If you
run more than one DHCP server on your network, you will experience network errors, such as conflicting IP
addresses. To disable DHCP on the Gateway, see the DHCP section in “Chapter 5: Configuring the Gateway.”

What is a VPN?

dsl: an always-on broadband connection
over traditional phone lines

ip address: the address used to identify
a computer or device on a network

dynamic ip address: a temporary IP
address assigned by a DHCP server

DHCP: a networking protocol that allows administrators to
assign temporary IP addresses to network computers by
"leasing" an IP address to a user for a limited amount of
time, instead of assigning permanent IP addresses

server: any computer whose function in a
network is to provide user access to files,
printing, communications, and other services

A VPN, or Virtual Private Network, is a connection between two endpoints - a VPN Gateway, for instance - in
different networks that allows private data to be sent securely over a shared or public network, such as the
Internet. This establishes a private network that can send data securely between these two locations or
networks.

This is done by creating a "tunnel". A VPN tunnel connects the two computers or networks and allows data to be
transmitted over the Internet as if it were still within those networks. Not a literal tunnel, it is a connection
secured by encrypting the data sent between the two networks.

VPN was created as a cost-effective alternative to using a private, dedicated, leased line for a private network.
Using industry standard encryption and authentication techniques - IPSec, short for IP Security - the VPN creates
a secure connection that, in effect, operates as if you were directly connected to your local network. Virtual
Private Networking can be used to create secure networks linking a central office with branch offices,

Chapter 2: Planning your Network
What is a VPN?

VPN: a security measure to protect data as it leaves
one network and goes to another over the Internet

encryption: encoding data transmitted in a network

IPSec: a VPN protocol used to implement

secure exchange of packets at the IP layer

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ADSL Gateway with 4-Port Switch

telecommuters, and/or professionals on the road (travelers can connect to a VPN Gateway using any computer
with VPN client software that supports IPSec, such as SSH Sentinel.)

There are two basic ways to create a VPN connection:

• VPN Gateway to VPN Gateway

• Computer (using VPN client software that supports IPSec) to VPN Gateway

The VPN Gateway creates a “tunnel” or channel between two endpoints, so that data transmissions between
them are secure. A computer with VPN client software that supports IPSec can be one of the two endpoints. Any
computer with the built-in IPSec Security Manager (Microsoft 2000 and XP ) allows the VPN Gateway to create a
VPN tunnel using IPSec (refer to “Appendix B: Configuring IPSec between a Windows 2000 or XP computer and
the VPN Gateway”). Other versions of Microsoft operating systems require additional, third-party VPN client
software applications that support IPSec to be installed.

Computer (using VPN client software that supports IPSec) to VPN Gateway

The following is an example of a computer-to-VPN Gateway VPN. In her hotel room, a traveling businesswoman
dials up her ISP. Her notebook computer has VPN client software that is configured with her office's VPN settings.
She accesses the VPN client software that supports IPSec and connects to the VPN Gateway at the central office.
As VPNs utilize the Internet, distance is not a factor. Using the VPN, the businesswoman now has a secure con­nection to the central office's network, as if she were physically connected.

VPN Gateway to VPN Gateway

An example of a VPN Gateway-to-VPN Gateway VPN would be as follows. At home, a telecommuter uses his VPN
Gateway for his always-on Internet connection. His Gateway is configured with his office's VPN settings. When he
connects to his office's Gateway, the two Gateways create a VPN tunnel, encrypting and decrypting data. As VPNs
utilize the Internet, distance is not a factor. Using the VPN, the telecommuter now has a secure connection to the
central office's network, as if he were physically connected.

For additional information and instructions about creating your own VPN, please visit Linksys’s website at
www.linksys.com or refer to “Appendix C: Configuring IPSec between a Windows 2000 or XP computer and the
VPN Gateway.”

Why do I need a VPN?

Computer networking provides a flexibility not available when using a paper-based system. With this flexibility,
however, comes an increased risk in security. This is why firewalls were first introduced. Firewalls help to protect

Chapter 2: Planning your Network
Why do I need a VPN?

Figure 2-2: Computer-to-VPN Gateway

IMPORTANT: You must have at least one VPN

Gateway on one end of the VPN tunnel. At the
other end of the VPN tunnel, you must have a
second VPN Gateway or a computer with VPN

client software that supports IPSec.

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ADSL Gateway with 4-Port Switch

data inside of a local network. But what do you do once information is sent outside of your local network, when
emails are sent to their destination, or when you have to connect to your company's network when you are out on
the road? How is your data protected?

That is when a VPN can help. VPNs secure data moving outside of your network as if it were still within that
network.

When data is sent out across the Internet from your computer, it is always open to attacks. You may already have
a firewall, which will help protect data moving around or held within your network from being corrupted or
intercepted by entities outside of your network, but once data moves outside of your network - when you send
data to someone via email or communicate with an individual over the Internet - the firewall will no longer protect
that data.

At this point, your data becomes open to hackers using a variety of methods to steal not only the data you are
transmitting but also your network login and security data. Some of the most common methods are as follows:

1) MAC Address Spoofing

Packets transmitted over a network, either your local network or the Internet, are preceded by a packet header.
These packet headers contain both the source and destination information for that packet to transmit efficiently.
A hacker can use this information to spoof (or fake) a MAC address allowed on the network. With this spoofed
MAC address, the hacker can also intercept information meant for another user.

2) Data Sniffing

Data "sniffing" is a method used by hackers to obtain network data as it travels through unsecured networks,
such as the Internet. Tools for just this kind of activity, such as protocol analyzers and network diagnostic tools,
are often built into operating systems and allow the data to be viewed in clear text.

3) Man in the Middle Attacks

Once the hacker has either sniffed or spoofed enough information, he can now perform a "man in the middle"
attack. This attack is performed, when data is being transmitted from one network to another, by rerouting the
data to a new destination. Even though the data is not received by its intended recipient, it appears that way to
the person sending the data.

These are only a few of the methods hackers use and they are always developing more. Without the security of
your VPN, your data is constantly open to such attacks as it travels over the Internet. Data travelling over the
Internet will often pass through many different servers around the world before reaching its final destination.
That's a long way to go for unsecured data and this is when a VPN serves its purpose.

Chapter 2: Planning your Network
Why do I need a VPN?

Figure 2-3: VPN Gateway-to-VPN Gateway

MAC Address: the unique address that a manufacturer
assigns to each networking device

firewall: a set of related programs located at a network
gateway server that protects the resources of a network
from users from other networks.

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ADSL Gateway with 4-Port Switch

Chapter 3: Getting to Know the ADSL Gateway

The Back Panel

Figure 3-1: Back Panel

The Gateway’s ports, where a network cable and DSL cable are connected, are located on the back panel. The
Gateway’s buttons are also located on the back panel.

Important: Resetting the Gateway to factory

LINE The LINE port connects to the ADSL line.

Ethernet (1-4) The Ethernet ports connect to your computer and other network devices.

Power The Power port is where you will connect the power adapter.

defaults will erase all of your settings and
replace them with the factory defaults. Do not
reset the Gateway if you want to retain these
settings.

Reset Button There are two ways to reset the Gateway's factory defaults. Either press the Reset Button, for

approximately ten seconds, or restore the defaults from the Factory Defaults screen of the
Administration tab in the Gateway’s Web-Based Utility.

On/Off This switch is used to turn the Gateway on or off.

With these, and many other, Linksys products, your networking options are limitless. Go to the Linksys website at
www.linksys.com for more information about products that work with the Gateway.

Chapter 3: Getting to Know the ADSL Gateway
The Back Panel

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ADSL Gateway with 4-Port Switch

The Front Panel

Figure 3-2: Front Panel

The Gateway's LEDs, where information about network activity is displayed, are located on the front panel.

Power Green. The Power LED lights up when the Gateway is powered on.

Ethernet (1-4) Green. The Ethernet LEDs serve two purposes. If an LED is continuously lit, the Gateway is

successfully connected to a device through that LAN port. If an LED is blinking, it is an
indication of any network activity on that port.

DSL Green. The DSL LED lights up whenever there is a successful DSL connection. The LED

blinks while establishing the ADSL connection.

Internet Green. The Internet LED lights up green when an Internet connection to the Internet

Service Provider (ISP) session is established. The Internet LED lights up red when the
connection to the ISP fails.

Chapter 3: Getting to Know the ADSL Gateway
The Front Panel

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ADSL Gateway with 4-Port Switch

Chapter 4: Connecting the ADSL Gateway

Overview

The Gateway’s setup consists of more than simply plugging hardware together. You will have to configure your
networked computers to accept the IP addresses that the Gateway assigns them (if applicable), and you will also
have to configure the Gateway with setting(s) provided by your Internet Service Provider (ISP).

After you have the setup information you need for your specific type of Internet connection, you can begin
installation and setup of the Gateway.

Connecting to a Computer

1. Before you begin, make sure that all of your network’s hardware is powered off, including the Gateway and
all computers.

2. Connect one end of an Ethernet network cable to one of the Ethernet ports (labeled 1-4) on the back of the
Gateway, and the other end to an Ethernet port on a computer.

3. Repeat this step to connect more computers, a switch, or other network devices to the Gateway.

IMPORTANT: If using microfilters, make sure to only place the microfilters
between the phone and the wall jack and not between the Gateway and
the wall jack or your ADSL will not connect.

hardware: the physical aspect of computers,
telecommunications, and other information technology devices

ISP: a company that provides access to the Internet

Figure 4-1: Connect your network

4. Connect a phone cable from the Line port on the Gateway’s back panel to the wall jack of the ADSL line. A
small device called a microfilter may be necessary between each phone and wall jack to prevent
interference. Contact your ISP if you have any questions.

Chapter 4: Connecting the ADSL Gateway
Overview

Figure 4-2: Connect your ADSL modem

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ADSL Gateway with 4-Port Switch

5. Connect the power adapter to the Gateway’s Power port, and then plug the power adapter into a power
outlet. Turn the On/Off switch to On.

• The Power LED on the front panel will light up green as soon as the power adapter is connected properly

and the switch is turned on. The Power LED will flash for a few seconds, then it will light up steady when
the self-test is complete. If the LED flashes for one minute or longer, see “Appendix A: Troubleshooting.”

6. Power on one of your computers that is connected to the Gateway.

The Gateway’s hardware installation is now complete.

IMPORTANT: Before configuring the Gateway, make sure that any computer connected to the

Gateway is configured to obtain its IP address from a DHCP server. Refer to Appendix E: Windows
Help on how to configure TCP/IP for automatic addressing and how to obtain an IP address
automatically if you haven’t already done so.

Figure 4-3: Connect power

NOTE: You should always plug the Gateway’s power

adapter into a power strip with surge protection.

TCP/IP: a set of instructions PCs use to
communicate over a network

Go to “Chapter 5: Configuring the Gateway.”

Chapter 4: Connecting the ADSL Gateway
Connecting to a Computer

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ADSL Gateway with 4-Port Switch

Chapter 5: Configuring the ADSL Gateway

Overview

Follow the steps in this chapter and use the Gateway’s web-based utility to configure the Gateway. This chapter
will describe each web page in the Utility and each page’s key functions. The utility can be accessed via your web
browser through use of a computer connected to the Gateway. For a basic network setup, most users only have to
use the following screens of the Utility:

• Basic Setup. On the Basic Setup screen, enter the settings provided by your ISP.

• Management. Click the Administration tab and then the Management tab. The Gateway’s default username
and password is admin. To secure the Gateway, change the Password from its default.

There are six main tabs: Setup, Security, Access Restrictions, Applications & Gaming, Administration, and Status.
Additional tabs will be available after you click one of the main tabs.

Setup

• Basic Setup. Enter the Internet connection and network settings on this screen.

• DDNS. To enable the Gateway’s Dynamic Domain Name System (DDNS) feature, complete the fields on this
screen.

• Advanced Routing. On this screen, you can alter Dynamic Routing, and Static Routing configurations.

Security

• Firewall. This screen contains Filters and Block WAN Requests. Filters block specific internal users from
accessing the Internet and block anonymous Internet requests.

• VPN. To enable or disable IPSec and/or PPTP Pass-through, and set up VPN tunnels, use this screen.

Access Restrictions

browser: an application program that provides a way to look at
and interact with all the information on the World Wide Web

Have You: Enabled TCP/IP on your computers?
computers communicate over the network with
this protocol. Refer to Appendix E: Windows Help
for more information on TCP/IP.

Note: For added security, you should change
the password through the Administration tab.

DDNS: allows the hosting of a website, FTP
server, or e-mail server with a fixed domain name
(e.g., www.xyz.com) and a dynamic IP address

static routing: forwarding data in
a network via a fixed path

WAN: the Internet

PPTP: a VPN protocol that allows the Point to Point Protocol

(PPP) to be tunneled through an IP network. This protocol is
also used as a type of broadband connection in Europe

• Internet Access. This screen allows you to prevent or permit only certain users from attaching to your
network.

Chapter 5: Configuring the ADSL Gateway
Overview

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ADSL Gateway with 4-Port Switch

Applications & Gaming

• Single Port Forwarding. Use this screen to set up common services or applications on your network.

• Port Range Forwarding. To set up public services or other specialized Internet applications on your network,
click this tab.

• Port Triggering. To set up triggered ranges and forwarded ranges for Internet applications, click this tab.

• DMZ. To allow one local user to be exposed to the Internet for use of special-purpose services, use this
screen.

Administration

• Management. On this screen, alter Gateway access privileges, SNMP, and UPnP settings.

• Reporting. If you want to view or save activity logs, click this tab.

• Diagnostics. Use this screen to do a Ping Test.

• Factory Defaults. If you want to restore the Gateway’s factory defaults, use this screen.

• Firmware Upgrade. Click this tab if you want to upgrade the Gateway’s firmware.

Status

• Gateway. This screen provides status information about the Gateway.

• Local Network. This provides status information about the local network.

• DSL Connection. This screen provides status information about the DSL connection.

How to Access the Web-based Utility

DMZ: removes the Router's firewall protection from one
PC, allowing it to be "seen" from the Internet

SNMP: a widely used network
monitoring and control protocol

ping:: an Internet utility used to determine
whether a particular IP address is online

firmware:: the programming code that runs a networking device

ipgrade:: to replace existing software or

firmware with a newer version

To access the web-based utility, launch Internet Explorer or Netscape Navigator, and enter the Gateway’s default
IP address, 192.168.1.1, in the Address field. Then press Enter.

A password request page will appear. (non-Windows XP users will see a similar screen.) Enter admin (the default
user name) in the User Name field, and enter admin (the default password) in the Password field. Then click the
OK button.

Chapter 5: Configuring the ADSL Gateway
How to Access the Web-based Utility

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ADSL Gateway with 4-Port Switch

The Setup Tab

Basic Setup

The first screen that appears is the Basic Setup tab. This tab allows you to change the Gateway's general
settings. Change these settings as described here and click the Save Settings button to save your changes or

Cancel Changes to cancel your changes.

Internet Setup

• ADSL Settings. The Gateway supports five Encapsulations: RFC 1483 Bridged, RFC 1483 Routed, RFC 2516
PPPoE, RFC 2364 PPPoA, and Bridged Mode Only. Each Basic Setup screen and available features will differ
depending on what type of encapsulation you select.

• VC Settings. Virtual Circuits (VPI and VCI): These fields consist of two items: VPI (Virtual Path Identifier) and VCI
(Virtual Channel Identifier). Your ISP will provide the correct settings for these fields. Multiplexing: Select LLC
or VC , depending on your ISP.

Figure 5-1: Password Screen

Chapter 5: Configuring the ADSL Gateway
The Setup Tab

Figure 5-2: Basic Setup Tab

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ADSL Gateway with 4-Port Switch

RFC 1483 Bridged

Dynamic IP

IP Settings. Select Obtain an IP Address Automatically if your ISP says you are connecting through a
dynamic IP address.

Static IP

If you are required to use a permanent IP address to connect to the Internet, then select Use the following IP
Address.

Figure 5-3: Internet Setup - Dynamic IP

static ip address: a fixed address assigned to a
computer or device that is connected to a network

• IP Address. This is the Gateway’s IP address, when seen from the WAN, or the Internet. Your ISP will

provide you with the IP Address you need to specify here.

• Subnet Mask. This is the Gateway’s Subnet Mask. Your ISP will provide you with the Subnet Mask.

• Default Gateway. Your ISP will provide you with the Default Gateway Address, which is the ISP server’s IP

address.

• Primary DNS. (Required) and Secondary DNS (Optional). Your ISP will provide you with at least one DNS

(Domain Name System) Server IP Address.

When finished making your changes on this tab, click the Save Settings button to save these changes, or
click the Cancel Changes button to undo your changes.

Chapter 5: Configuring the ADSL Gateway
The Setup Tab

Figure 5-4: Internet Setup - Static IP

default gateway: a device that forwards
Internet traffic from your local area

dns: the IP address of your ISP's server, which
translates the names of websites into IP addresses

15

ADSL Gateway with 4-Port Switch

RFC 1483 Routed

If you are required to use RFC 1483 Routed, then select RFC 1483 Routed.

• IP Address. This is the Gateway’s IP address, when seen from the WAN, or the Internet. Your ISP will

provide you with the IP Address you need to specify here.

• Subnet Mask. This is the Gateway’s Subnet Mask. Your ISP will provide you with the Subnet Mask.

• Default Gateway. Your ISP will provide you with the Default Gateway Address, which is the ISP server’s IP

address.

• Primary DNS. (Required) and Secondary DNS (Optional). Your ISP will provide you with at least one DNS

(Domain Name System) Server IP Address.

RFC 2516 PPPoE

Some DSL-based ISPs use PPPoE (Point-to-Point Protocol over Ethernet) to establish Internet connections. If
your ISP uses a PPPoE connection, enable PPPoE.

• Service Name. Enter the Service Name, if required by your ISP.

• User Name and Password. Enter the User Name and Password provided by your ISP.

• Connect on Demand: Max Idle Time. You can configure the Gateway to disconnect the Internet connection

after it has been inactive for a specified period of time (Max Idle Time). If your Internet connection has
been terminated due to inactivity, Connect on Demand enables the Gateway to automatically re-establish
your connection as soon as you attempt to access the Internet again. If you wish to activate Connect on
Demand, click the radio button. In the Max Idle Time field, enter the number of minutes you want to have
elapsed before your Internet connection terminates.

• Keep Alive: Redial Period. If you select this option, the Gateway will periodically check your Internet

connection. If you are disconnected, then the Gateway will automatically re-establish your connection. To
use this option, click the radio button next to Keep Alive. In the Redial Period field, you specify how often
you want the Gateway to check the Internet connection. The default Redial Period is 30 seconds.

When finished making your changes on this tab, click the Save Settings button to save these changes, or
click the Cancel Changes button to undo your changes.

Figure 5-5: Internet Setup - RFC 1483 Routed

PPPoE: a type of broadband connection that
provides authentication (username and
password) in addition to data transport

Figure 5-6: Internet Setup - RFC 2516 PPPoE

Chapter 5: Configuring the ADSL Gateway
The Setup Tab

16

ADSL Gateway with 4-Port Switch

RFC 2364 PPPoA

Some DSL-based ISPs use PPPoA (Point-to-Point Protocol over ATM) to establish Internet connections. If your
ISP uses a PPPoA, enable PPPoA.

• User Name and Password. Enter the User Name and Password provided by your ISP.

• Connect on Demand: Max Idle Time. You can configure the Gateway to cut the Internet connection after it

has been inactive for a specified period of time (Max Idle Time). If your Internet connection has been
terminated due to inactivity, Connect on Demand enables the Gateway to automatically re-establish your
connection as soon as you attempt to access the Internet again. If you wish to activate Connect on
Demand, click the radio button. In the Max Idle Time field, enter the number of minutes you want to have
elapsed before your Internet connection terminates.

• Keep Alive Option: Redial Period. If you select this option, the Gateway will periodically check your

Internet connection. If you are disconnected, then the Gateway will automatically re-establish your
connection. To use this option, click the radio button next to Keep Alive. In the Redial Period field, you
specify how often you want the Gateway to check the Internet connection. The default Redial Period is 30
seconds.

When finished making your changes on this tab, click the Save Settings button to save these changes, or
click the Cancel Changes button to undo your changes.

Figure 5-7: Internet Setup - RFC 2364 PPPoA

Bridged Mode Only

If you are using your Gateway as a bridge, which makes the Gateway act like a standalone modem, select
Bridged Mode Only. All NAT and routing is disabled in this mode.

When finished making your changes on this tab, click the Save Settings button to save these changes, or
click the Cancel Changes button to undo your changes.

Chapter 5: Configuring the ADSL Gateway
The Setup Tab

Figure 5-8: Internet Setup - Bridged Mode Only

NAT: translates IP addresses of a local area
network to a different IP address for the Internet

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