Netgear DG632 Reference Guide

Reference Manual for the Model DG632 ADSL Modem Router

NETGEAR, Inc.
4500 Great America Parkway Santa Clara, CA 95054 USA Phone 1-888-NETGEAR
April 2004
© 2004 by NETGEAR, Inc. All rights reserved. April 2004.
Trademarks
NETGEAR is a trademark of Netgear, Inc.
Microsoft, Windows, and Windows NT are registered trademarks of Microsoft Corporation.
Other brand and product names are registered trademarks or trademarks of their respective holders.
Statement of Conditions
In the interest of improving internal design, operational function, and/or reliability, NETGEAR reserves the right to make changes to the products described in this document without notice.
NETGEAR does not assume any liability that may occur due to the use or application of the product(s) or circuit layout(s) described herein.
Federal Communications Commission (FCC) Compliance Notice: Radio Frequency Notice
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.
Federal Communications Commission (FCC) Radiation Exposure Statement
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. In order to avoid the possibility of exceeding the FCC radio frequency exposure limits, human proximity to the antenna shall not be less than 20 cm (8 inches) during normal operation.
EN 55 022 Declaration of Conformance
This is to certify that the DG632 ADSL Modem Router is shielded against the generation of radio interference in accordance with the application of Council Directive 89/336/EEC, Article 4a. Conformity is declared by the application of EN 55 022 Class B (CISPR 22).
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Bestätigung des Herstellers/Importeurs
Es wird hiermit bestätigt, daß das DG632 ADSL Modem Router gemäß der im BMPT-AmtsblVfg 243/1991 und Vfg 46/ 1992 aufgeführten Bestimmungen entstört ist. Das vorschriftsmäßige Betreiben einiger Geräte (z.B. Testsender) kann jedoch gewissen Beschränkungen unterliegen. Lesen Sie dazu bitte die Anmerkungen in der Betriebsanleitung.
Das Bundesamt für Zulassungen in der Telekommunikation wurde davon unterrichtet, daß dieses Gerät auf den Markt gebracht wurde und es ist berechtigt, die Serie auf die Erfüllung der Vorschriften hin zu überprüfen.
Certificate of the Manufacturer/Importer
It is hereby certified that the DG632 ADSL Modem Router has been suppressed in accordance with the conditions set out in the BMPT-AmtsblVfg 243/1991 and Vfg 46/1992. The operation of some equipment (for example, test transmitters) in accordance with the regulations may, however, be subject to certain restrictions. Please refer to the notes in the operating instructions.
Federal Office for Telecommunications Approvals has been notified of the placing of this equipment on the market and has been granted the right to test the series for compliance with the regulations.
Voluntary Control Council for Interference (VCCI) Statement
This equipment is in the second category (information equipment to be used in a residential area or an adjacent area thereto) and conforms to the standards set by the Voluntary Control Council for Interference by Data Processing Equipment and Electronic Office Machines aimed at preventing radio interference in such residential areas.
When used near a radio or TV receiver, it may become the cause of radio interference.
Read instructions for correct handling.
Customer Support
Refer to the Support Information Card that shipped with your DG632 ADSL Modem Router.
World Wide Web
NETGEAR maintains a World Wide Web home page that you can access at the universal resource locator (URL) http://www.netgear.com. A direct connection to the Internet and a Web browser such as Internet Explorer or Netscape are required.
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Contents

Chapter 1 About This Manual
Audience, Conventions, Scope ......................................................................................1-1
How to Use this Manual ..................................................................................................1-2
How to Print this Manual .................................................................................................1-3
Chapter 2 Introduction
About the Modem ...........................................................................................................2-1
Key Features ..................................................................................................................2-1
Modem or Router Device Mode ...............................................................................2-2
Modem Device Mode .........................................................................................2-2
Router Device Mode .......................................................................................... 2-2
A Powerful, True Firewall .........................................................................................2-3
Auto Sensing and Auto Uplink™ LAN Ethernet Connections .................................. 2-3
Easy Installation and Management ..........................................................................2-4
What’s in the Box? ..........................................................................................................2-5
The Front Panel ....................................................................................................... 2-6
The Rear Panel ........................................................................................................2-7
Chapter 3 Connecting the Modem to the Internet
What You Need Before You Begin ..................................................................................3-1
ADSL Microfilter Requirements ................................................................................3-1
ADSL Microfilter .................................................................................................3-1
ADSL Microfilter with Built-In Splitter .................................................................3-2
Computer Hardware Requirements .........................................................................3-2
Ethernet Cabling Requirements ............................................................................... 3-2
LAN Configuration Requirements ............................................................................3-2
Internet Configuration Requirements ....................................................................... 3-3
Where Do I Get the Internet Configuration Parameters? .........................................3-3
Contents v
Record Your Internet Connection Information ..........................................................3-4
Connecting the DG632 to Your Network .........................................................................3-5
How to Connect the Modem .....................................................................................3-5
Auto-Detecting Your Internet Connection Type ........................................................3-9
Wizard-Detected PPPoE Login Account Setup ......................................................3-10
Wizard-Detected PPPoA Login Account Setup ...................................................... 3-11
Wizard-Detected Dynamic IP Account Setup ......................................................... 3-11
Testing Your Internet Connection ..................................................................................3-12
Connecting Your Computer to the DG632 USB Port Option ........................................3-12
Chapter 4 Maintaining Your DG632 ADSL Modem Router
Changing the Mode of Operation ...................................................................................4-1
Changing the Password of Your DG632 ADSL Modem Router ...................................... 4-3
How to Change the Built-In Password .....................................................................4-4
Changing the Administrator Login Timeout .............................................................. 4-4
Backing Up, Restoring, or Erasing Your Settings ...........................................................4-5
How to Back Up the Configuration to a File ............................................................. 4-5
How to Restore the Configuration from a File ..........................................................4-6
How to Erase the Configuration ...............................................................................4-6
Upgrading the Modem’s Firmware ................................................................................. 4-6
How to Upgrade the Modem Firmware ....................................................................4-7
Chapter 5 Using Modem Mode
Modem Mode Basic Settings ..........................................................................................5-1
Manually Configuring Basic Settings ........................................................................ 5-1
Internet Connection Requires Login and Uses PPPoE ............................................5-2
Internet Connection Requires Login and Uses PPPoA ............................................5-2
Internet Connection Does Not Require A Login ....................................................... 5-3
ADSL Settings ..........................................................................................................5-4
Modem Mode Network Management Information ..........................................................5-5
Viewing Modem Status and Usage Statistics ...........................................................5-5
Chapter 6 Using Router Mode
Router Mode Basic Settings ...........................................................................................6-1
Manually Configuring Basic Settings ........................................................................ 6-2
vi Contents
Internet Connection Requires Login and Uses PPPoE ............................................6-3
Internet Connection Requires Login and Uses PPPoA ............................................6-3
Internet Connection Does Not Require A Login ....................................................... 6-4
ADSL Settings ..........................................................................................................6-5
Router Mode Network Management Information ............................................................6-6
Viewing Router Status and Usage Statistics ............................................................ 6-6
Viewing, Selecting, and Saving Router Mode Logged Information ........................ 6-11
Selecting What Information to Log ..................................................................6-12
Saving Log Files on a Server ..........................................................................6-12
Router Mode Diagnostic Utilities and Rebooting ..........................................................6-13
Firewall Services ..........................................................................................................6-14
How to Define Services ..........................................................................................6-14
Firewall Rules ...............................................................................................................6-15
Inbound Rules (Port Forwarding) ...........................................................................6-16
Inbound Rule Example: A Local Public Web Server ........................................6-17
Considerations for Inbound Rules ...................................................................6-17
Outbound Rules (Service Blocking) ....................................................................... 6-18
Outbound Rule Example: Doom ...................................................................... 6-18
Configuring Advanced Settings ....................................................................................6-19
Setting Up A Default DMZ Server .......................................................................... 6-19
How to Configure a Default DMZ Server .........................................................6-20
Connect Automatically, as Required ...................................................................... 6-20
Disable Port Scan and DOS Protection .................................................................6-21
Respond to Ping on Internet WAN Port .................................................................6-21
MTU Size ...............................................................................................................6-21
Configuring LAN IP Settings ......................................................................................... 6-21
DHCP .....................................................................................................................6-23
Use Router as DHCP server ...........................................................................6-23
Reserved IP addresses ...................................................................................6-24
How to Configure LAN TCP/IP Settings ................................................................. 6-25
Using Static Routes ...................................................................................................... 6-25
Static Route Example .............................................................................................6-25
How to Configure Static Routes .............................................................................6-26
Contents vii
Chapter 7 Troubleshooting
Basic Functioning ........................................................................................................... 7-1
Power LED Not On ................................................................................................... 7-2
LAN or WAN Port LEDs Not On ...............................................................................7-2
Troubleshooting the Web Configuration Interface ..........................................................7-2
Troubleshooting the ISP Connection ..............................................................................7-3
ADSL link .................................................................................................................7-3
WAN LED Blinking Yellow .................................................................................. 7-4
WAN LED Off .....................................................................................................7-4
Obtaining a WAN IP Address ...................................................................................7-4
Troubleshooting PPPoE or PPPoA ..........................................................................7-5
Troubleshooting Internet Browsing ..........................................................................7-6
Troubleshooting a TCP/IP Network Using the Ping Utility ..............................................7-6
Testing the LAN Path to Your Router .......................................................................7-6
Testing the Path from Your Computer to a Remote Device .....................................7-7
Restoring the Default Configuration and Password ........................................................7-8
Using the Reset button .............................................................................................7-8
Appendix A Technical Specifications
Appendix B Network and Routing Basics
Related Publications ...................................................................................................... B-1
Basic Router Concepts .................................................................................................. B-1
What is a Router? ................................................................................................... B-2
Routing Information Protocol ................................................................................... B-2
IP Addresses and the Internet ................................................................................. B-2
Netmask .................................................................................................................. B-4
Subnet Addressing .................................................................................................. B-5
Private IP Addresses ............................................................................................... B-7
Single IP Address Operation Using NAT ................................................................. B-8
MAC Addresses and Address Resolution Protocol ................................................. B-9
Related Documents ................................................................................................. B-9
Domain Name Server ............................................................................................ B-10
IP Configuration by DHCP .................................................................................... B-10
viii Contents
Internet Security and Firewalls .................................................................................... B-10
What is a Firewall? .................................................................................................B-11
Stateful Packet Inspection ......................................................................................B-11
Denial of Service Attack .........................................................................................B-11
Ethernet Cabling ...........................................................................................................B-11
Category 5 Cable Quality ...................................................................................... B-12
Inside Twisted Pair Cables .................................................................................... B-13
Uplink Switches, Crossover Cables, and MDI/MDIX Switching ............................ B-14
Appendix C Preparing Your Network
Preparing Your Computers for TCP/IP Networking ....................................................... C-1
Configuring Windows 95, 98, and Me for TCP/IP Networking ....................................... C-2
Installing or Verifying Windows Networking Components ....................................... C-2
Enabling DHCP to Automatically Configure TCP/IP Settings in Windows 95B, 98, and Me C-4
Selecting the Windows’ Internet Access Method .................................................... C-6
Verifying TCP/IP Properties .................................................................................... C-6
Configuring Windows NT4, 2000 or XP for IP Networking ............................................ C-7
Installing or Verifying Windows Networking Components ....................................... C-7
DHCP Configuration of TCP/IP in Windows XP, 2000, or NT4 ...................................... C-8
DHCP Configuration of TCP/IP in Windows XP ..................................................... C-8
DHCP Configuration of TCP/IP in Windows 2000 ................................................ C-10
DHCP Configuration of TCP/IP in Windows NT4 .................................................. C-13
Verifying TCP/IP Properties for Windows XP, 2000, and NT4 .............................. C-15
Configuring the Macintosh for TCP/IP Networking ...................................................... C-16
MacOS 8.6 or 9.x .................................................................................................. C-16
MacOS X ............................................................................................................... C-16
Verifying TCP/IP Properties for Macintosh Computers ......................................... C-17
Verifying the Readiness of Your Internet Account ....................................................... C-18
Are Login Protocols Used? ................................................................................... C-18
What Is Your Configuration Information? .............................................................. C-18
Obtaining ISP Configuration Information for Windows Computers ....................... C-19
Obtaining ISP Configuration Information for Macintosh Computers ..................... C-20
Restarting the Network ................................................................................................ C-21
Glossary
Contents ix
x Contents
Chapter 1
About This Manual
Congratulations on your purchase of the NETGEAR® DG632 ADSL Modem Router. This chapter introduces important features of this manual.

Audience, Conventions, Scope

This reference manual assumes that the reader has basic-to-intermediate computer and Internet skills. However, basic computer network, Internet, firewall, and networking technology tutorial information is provided in the appendices.
This guide uses the following typographical conventions:
Table 1. Typographical conventions
italics Emphasis, books, CDs, URL names
bold User input
mono space Screen text, file and server names, extensions, commands, IP addresses
This guide uses the following formats to highlight special messages:
Note: This format is used to highlight information of importance or special interest.
This manual is written according to these specifications.
Table 1-1. Manual Specifications
Product Version DG632 ADSL Modem Router
Manual Publication Date April 2004
Note: Product updates are available on the NETGEAR, Inc. Web site at
http://kbserver.netgear.com/products/DG632.asp.
About This Manual 1-1
Reference Manual for the Model DG632 ADSL Modem Router

How to Use this Manual

The HTML version of this manual includes a variety of navigation features as well as links to PDF versions of the full manual and individual chapters.
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Figure Preface -2: HTML version of this manual
1. Left pane. Use the left pane to view the Contents, Index, Search, and Favorites tabs.
To view the HTML version of the manual, you must have a version 4 or later IE or Netscape browser with JavaScript enabled.
2. Toolbar buttons. Use the toolbar buttons across the top to navigate, print pages, and more.
The Show in Contents button locates the current topic in the Contents tab.
Previous/Next buttons display the previous or next topic.
The PDF button links to a PDF version of the full manual.
The Print button prints the current topic. Using this button when a step-by-step procedure is displayed will send the entire procedure to your printer. You do not have to worry about specifying the correct range of pages.
3. Right pane. Use the right pane to view the contents of the manual. Also, each page of the manual includes a link at the top right which links to a PDF file containing just the currently selected chapter of the manual.
1-2 About This Manual
Reference Manual for the Model DG632 ADSL Modem Router

How to Print this Manual

To print this manual you may choose one of the following options, according to your needs:
Printing a “How To” Sequence of Steps in the HTML View. Use the Print button on the upper right of the toolbar to print the currently displayed topic. Using this button when a step-by-step procedure is displayed will send the entire procedure to your printer. You do not have to worry about specifying the correct range of pages.
Printing a Chapter. Use the link at the top right of any page.
Click the “PDF of This Chapter” link at the top right of any page in the chapter you want
to print. The PDF version of the chapter you were viewing opens in a browser window.
Note: Your computer must have the free Adobe Acrobat reader installed in order to view and print PDF files. The Acrobat reader is available on the Adobe Web site at
http://www.adobe.com.
Click the print icon in the upper left of the window.
Tip: If your printer supports printing two pages on a single sheet of paper, you can save paper and printer ink by selecting this feature.
Printing the Full Manual. Use the PDF button in the toolbar at the top right of the browser window.
Click the PDF button on the upper right of the toolbar. The PDF version of the
chapter you were viewing opens in a browser window.
Click the print icon in the upper left of the window.
Tip: If your printer supports printing two pages on a single sheet of paper, you can save paper and printer ink by selecting this feature.
About This Manual 1-3
Reference Manual for the Model DG632 ADSL Modem Router
1-4 About This Manual
Chapter 2
Introduction
This chapter describes the features of the NETGEAR DG632 ADSL Modem Router. The DG632 modem router is a combination of a built-in ADSL modem, router, and firewall which enables your network to safely share an Internet connection that otherwise is used by a single computer.
Note: If you are unfamiliar with networking and routing, refer to Appendix B, “Network
and Routing Basics” to become more familiar with the terms and procedures used in this
manual.

About the Modem

The DG632 ADSL Modem Router provides continuous, high-speed 10/100 Ethernet access between your Ethernet devices. The DG632 modem router enables your network to share an Internet connection through the built-in ADSL modem that otherwise is used by a single computer. With minimum setup, you can install and use the modem within minutes.
The included firewall and Network Address Translation (NAT) features protect you from hackers.

Key Features

The DG632 modem router provides the following features:
A powerful, true firewall
Auto Sensing and Auto Uplink™ LAN Ethernet connections
Extensive Internet protocol support
Easy, Web-based setup for installation and management
Direct connection to the Internet using the built-in ADSL modem
USB connection to your computer eliminates the need for installing an Ethernet card
Modem or Router Device Mode
Introduction 2-1
Reference Manual for the Model DG632 ADSL Modem Router
Modem Device Mode supports configuration of your Internet connection on your
computer, and running software on your computer to log in to your ISP, if needed.
Router Device Mode supports configuration of your Internet connection on your
DG632 modem router, and can be configured to automatically log in to your ISP, if needed.
These features are discussed below.

Modem or Router Device Mode

The DG632 modem router can be set to operate in either Modem Device Mode or Router Device Mode.
Modem Device Mode
When set to operate in Modem Device Mode, your computer must be configured for whatever settings your ISP requires. Also, if your ISP uses software to establish your Internet connection, the DHCP spoofing feature will eliminate the need to run that software.
When DHCP spoofing is enabled, the modem obtains the actual Internet WAN IP address from the ISP during connection setup and forwards it to the attached computer.
Router Device Mode
In Router Device Mode, the DG632 supports configuration of the Transmission Control Protocol/ Internet Protocol (TCP/IP) parameters and login functions on the modem.
The DG632 supports Transmission Control Protocol/Internet Protocol (TCP/IP) and Routing Information Protocol (RIP). Appendix B, “Network and Routing Basics” provides further information on TCP/IP.
Automatic Configuration of Attached PCs by DHCP The DG632 dynamically assigns network configuration information, including IP, modem, and domain name server (DNS) addresses, to attached PCs on the LAN using the Dynamic Host Configuration Protocol (DHCP). This feature greatly simplifies configuration of PCs on your local network.
DNS Proxy When DHCP is enabled and no DNS addresses are specified, the modem provides its own address as a DNS server to the attached PCs. The modem obtains actual DNS addresses from the ISP during connection setup and forwards DNS requests from the LAN.
2-2 Introduction
Reference Manual for the Model DG632 ADSL Modem Router
Classical IP (RFC 1577) Some Internet service providers, in Europe for example, use Classical IP in their ADSL services. In such cases, the modem is able to use the Classical IP address from the ISP.
PPP over Ethernet (PPPoE) PPP over Ethernet is a protocol for connecting remote hosts to the Internet over an ADSL connection by simulating a dial-up connection. This feature eliminates the need to run a login program such as EnterNet or WinPOET on your computer.
PPP over ATM (PPPoA) PPP over ATM is a protocol for connecting remote hosts to the Internet over an ADSL connection by simulating an ATM connection.

A Powerful, True Firewall

Unlike simple Internet sharing NAT routers, the DG632 is a true firewall, using stateful packet inspection to defend against hacker attacks. Its firewall features include:
Denial of Service (DoS) protection Automatically detects and thwarts Denial of Service (DoS) attacks such as Ping of Death, SYN Flood, LAND Attack and IP Spoofing.
Blocks unwanted traffic from the Internet to your LAN.
Blocks access from your LAN to Internet locations or services that you specify as off-limits.
Logs security incidents The DG632 will log security events such as blocked incoming traffic, port scans, attacks, and administrator logins.

Auto Sensing and Auto Uplink™ LAN Ethernet Connections

The DG632 can connect to either a 10 Mbps standard Ethernet network or a 100 Mbps Fast Ethernet network. The local LAN port is autosensing and capable of full-duplex or half-duplex operation.
TM
The modem incorporates Auto Uplink sense whether the Ethernet cable plugged into the port should have a ‘normal’ connection such as to a computer or an ‘uplink’ connection such as to a switch or hub. That port will then configure itself to the correct configuration. This feature also eliminates the need to worry about crossover cables, as Auto Uplink will accommodate either type of cable to make the right connection.
Introduction 2-3
technology. The local Ethernet port will automatically
Reference Manual for the Model DG632 ADSL Modem Router

Easy Installation and Management

You can install, configure, and operate the DG632 within minutes after connecting it to the network. The following features simplify installation and management tasks:
Browser-based management Browser-based configuration allows you to easily configure your modem from almost any type of personal computer, such as Windows, Macintosh, or Linux. A user-friendly Setup Wizard is provided and online help documentation is built into the browser-based Web Management Interface.
Smart Wizard The modem automatically senses the type of Internet connection, asking you only for the information required for your type of ISP account.
Diagnostic functions The modem incorporates built-in diagnostic functions such as Ping, and DNS lookup. These functions allow you to test Internet connectivity.
Visual monitoring The modem’s front panel LEDs provide an easy way to monitor its status and activity.
Flash erasable programmable read-only memory (EPROM) for firmware upgrade
2-4 Introduction
Reference Manual for the Model DG632 ADSL Modem Router

What’s In The Box?

The product package should contain the following items.
ADSL Firewall Router DG632
DG632 ADSL Firewall Router Resource CD,installation guide, support information card & warranty/registration card
L
I
NE
LTER
I
SLF
D
E
ON
H
P
L
DS
PN
H
Power adapter
Category 5 100 Mbps Ethernet cable
Micro Filter
Phone Cable
Figure 2-1: DG632 Package contents
DG632 ADSL Modem Router
AC power adapter (varies by region)
Category 5 (Cat 5) Ethernet cable
Microfilters (quantity and type vary by region)
USB Cable (depending on the country of purchase)
Telephone cable
Microfilters (quantity and type vary by region)
ADSL Modem Router Resource CD, including: —This guide — Application Notes
Introduction 2-5
Reference Manual for the Model DG632 ADSL Modem Router
DG632 ADSL Modem Router Installation Guide
A Printed Quick Installation Guide
Warranty and Support Information Cards
If any of the parts are incorrect, missing, or damaged, contact your NETGEAR dealer. Keep the carton, including the original packing materials, in case you need to return the router for repair.

The Front Panel

The DG632 ADSL Modem Router front panel shown below contains status LEDs.
Power USBInternet Ethernet
Figure 2-2: DG632 Front Panel
You can use the LEDs to verify various conditions. Table 2- 1 lists and describes each LED on the front panel of the modem. These LEDs are green when lit.
Table 2-1. LED Descriptions
Label Activity Description
Power On
Off
Internet Blink — Amber
On — Green Blink — Green
2-6 Introduction
Power is supplied to the modem. Power is not supplied to the modem.
Indicates ADSL training. The Internet port has detected a link with an attached device. Data is being transmitted or received by the Internet port.
Table 2-1. LED Descriptions
Reference Manual for the Model DG632 ADSL Modem Router
USB On
Off
Ethernet On (Green)
Blink (Green) On (Amber) Blink (Amber) Off
The Local port has detected link with a device. No link is detected on this port.
The Local port has detected link with a 100 Mbps device. Data is being transmitted or received at 100 Mbps. The Local port has detected link with a 10 Mbps device. Data is being transmitted or received at 10 Mbps. No link is detected on this port.

The Rear Panel

The rear panel of the DG632 ADSL Modem Router (Figure 2-3) contains port connections.
Internet Ethernet
USB
Figure 2-3: DG632 Rear Panel
Power
Viewed from left to right, the rear panel contains the following elements:
ADSL port for connecting to an ADSL line
USB port for connecting to a local computer
Ethernet RJ-45 port for connecting to a local computer
Factory Default Reset push button
AC power adapter outlet
Introduction 2-7
Reference Manual for the Model DG632 ADSL Modem Router
2-8 Introduction
Chapter 3
Connecting the Modem to the Internet
This chapter describes how to set up the modem on your Local Area Network (LAN) and connect to the Internet. It describes how to configure your DG632 ADSL Modem Router for Internet access using the Setup Wizard, or how to manually configure your Internet connection.

What You Need Before You Begin

You need to prepare these three things before you can establish an Internet connection through your modem:
1. The modem connected to an ADSL line and a computer properly connected to the modem as
explained below.
2. Active Internet service such as that provided by an ADSL account.
3. The Internet Service Provider (ISP) configuration information for your DSL account.

ADSL Microfilter Requirements

ADSL technology uses the same wires as your telephone service. However, ADSL adds signals to the telephone lines which create noise in the telephone service. You must use ADSL microfilters to filter out these signals before they reach your telephone.
ADSL Microfilter
Phone
Figure 3-1: ADSL microfilter
Each device such as a telephone, fax machine, answering machine, or caller ID display will require an ADSL microfilter.
Connecting the Modem to the Internet 3-1
Reference Manual for the Model DG632 ADSL Modem Router
Note: Do not connect the DG632 to the ADSL line through a microfilter unless the microfilter is a
combination microfilter/splitter specifically designed for this purpose. Doing so will prevent the built-in ADSL modem in the DG632 from establishing a connection to the Internet. If you have any doubts about this, connect the DG632 directly to the ADSL line.
ADSL Microfilter with Built-In Splitter
DSL Phone
Figure 3-2: ADSL microfilter with built-in splitter
Line
Use an ADSL microfilter with built-in splitter when there is a single wall outlet which must provide connectivity for both the DG632 and telephone equipment.

Computer Hardware Requirements

To use the DG632 modem router on your network, each computer must have an installed Ethernet adapter and an Ethernet cable.
To install and run the DG632 modem router with your computer, the computer must have an installed Ethernet Network Interface Card (NIC) and an Ethernet cable or an available USB port.

Ethernet Cabling Requirements

The DG632 modem router connects to your Ethernet LAN via twisted-pair cables. If the computer will connect to your network at 100 Mbps, you must use a Category 5 (CAT5) cable such as the one provided with your modem.

LAN Configuration Requirements

For the initial connection to the Internet and configuration of your modem, you need to connect a computer to the modem which is set to automatically get its TCP/IP configuration from the modem via DHCP.
Note: Please refer to Appendix C, “Preparing Your Network” for assistance with DHCP
configuration.
3-2 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router

Internet Configuration Requirements

Depending on how your ISP set up your Internet account, you need one or more of these configuration parameters to connect your modem to the Internet:
Virtual Path Identifier (VPI)/Virtual Channel Indentifier (VCI) parameters
Multiplexing Method
Host and Domain Names
ISP Login Name and Password
ISP Domain Name Server (DNS) Addresses
Fixed or Static IP Address

Where Do I Get the Internet Configuration Parameters?

There are several ways you can gather the required Internet connection information.
Your ISP should have provided you with all the information needed to connect to the Internet. If you cannot locate this information, you can ask your ISP to provide it or you can try one of the options below.
If you have a computer already connected using the active Internet access account, you can gather the configuration information from that computer.
For Windows 95/98/ME, open the Network control panel, select the TCP/IP entry for the
Ethernet adapter, and click Properties.
For Windows 2000/XP, open the Local Area Network Connection, select the TCP/IP entry
for the Ethernet adapter, and click Properties.
For Macintosh computers, open the TCP/IP or Network control panel.
You can also refer to the ADSL Modem Router Resource CD for the NETGEAR Router ISP Guide which provides Internet connection information for many ISPs.
Once you locate your Internet configuration parameters, you may want to record them on the page below according to the instructions in “Record Your Internet Connection Information” on page
3-4.
Connecting the Modem to the Internet 3-3
Reference Manual for the Model DG632 ADSL Modem Router

Record Your Internet Connection Information

Print this page. Fill in the configuration parameters from your Internet Service Provider (ISP).
ISP Multiplexing Method and Virtual Circuit Number: The default settings of your DG632 ADSL Modem Router will work fine for most ISPs. However, some ISPs use a specific Multiplexing Method or a Virtual Circuit Number for either the Virtual Path Identifier (VPI) or Virtual Channel Identifier (VCI). If your ISP provided you with a specific Multiplexing Method or VPI/VCI number, then fill in the following:
Multiplexing Method, circle one: LLC-based or VC-based VPI: ________
65535.
ISP Login Name: The login name and password are case sensitive and must be entered exactly as given by your ISP. Some ISPs use your full e-mail address as the login name. The Service Name is not required by all ISPs. If you use a login name and password, then fill in the following:
A number between 0 and 255. VCI: ___________ A number between 1 and
Login Name: ______________________________
Password: ____________________________
Service Name: _____________________________
Fixed or Static IP Address: If you have a static IP address, record the following information. For example, 169.254.141.148 could be a valid IP address.
Fixed or Static Internet IP Address: ______
.______.______.______ Modem IP Address: ______.______.______.______ Subnet Mask: ______.______.______.______
ISP DNS Server Addresses: If you were given DNS server addresses, fill in the following:
Primary DNS Server IP Address: ______
.______.______.______
Secondary DNS Server IP Address: ______.______.______.______
Host and Domain Names: Some ISPs use a specific host or domain name like CCA7324-A or home. If you did not get host or domain names, use the following examples as a guide:
If your main e-mail account with your ISP is aaa@yyy.com, then use aaa as your host name.
Your ISP might call this your account, user, host, computer, or system name.
If your ISP’s mail server is mail.xxx.yyy.com, then use xxx.yyy.com as the domain name.
ISP Host Name: _________________________
ISP Domain Name: _______________________
3-4 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router

Connecting the DG632 to Your Network

This section provides instructions for connecting the DG632 modem router to your network.
Note: The Resource CD included with your modem contains an animated Installation Assistant to
help you through this procedure.

How to Connect the Modem

There are three steps to connecting your firewall:
1. Connect the modem to your ADSL line.
2. Connect the modem to the computers on your network.
3. Log in to the modem.
4. Connect to the Internet.
Follow the steps below to connect your modem to your network. Before you begin, locate the ADSL configuration information from your Internet Service Provider (ISP).
1. CONNECT THE DG632 TO THE ADSL LINE.
a. You need to install a filter on every telephone or device that shares the same phone
number as your ADSL modem. Select the filter that came with your modem.
One-Line Filter
Phone
Two-Line Filter
With Splitter
DSL
Phone
Line
Figure 3-3: ADSL microfilters
Note: If you purchased the DG632 in a country where the filter is not included, you must acquire one.
Connecting the Modem to the Internet 3-5
Splitter
Reference Manual for the Model DG632 ADSL Modem Router
Two-Line Filter Example. Insert the two-line filter into the phone outlet and connect the
b.
phone to the phone line connector (A).
$3,
3KRQH
,INE
A
Phone Line
Figure 3-4: Connecting an ADSL microfilter and phone
Note: To use a one-line filter with a separate splitter, insert the splitter into the phone outlet, connect the one-line filter to the splitter, and connect the phone to the filter.
2. CONNECT THE DG632 TO THE INTERNET.
Note: Improperly connecting a filter to your DG632 modem router will block your ADSL connection.
a. Turn off your computer.
b. Connect the ADSL port of the DG632 to the ADSL port (B) of the two-line filter.
ADSL Port
B
'6/
0HONE
,INE
Figure 3-5: Connecting DG632 modem router to an ADSL microfilter and phone
3-6 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router
Connect the Ethernet cable (C) from your DG632’s LAN port to the Ethernet adapter in
c.
your computer.
Note: To connect the computer using the USB port, please see “Connecting Your
Computer to the DG632 USB Port Option” on page 3-12.
C
$3,
0HONE
,INE
Figure 3-6: Connecting a computer to the DG632 modem router
Note: The DG632 modem router incorporates Auto UplinkTM technology. The Ethernet port will automatically sense whether the cable plugged into the port should have a 'normal' connection (for example, connecting to a computer) or an 'uplink' connection (for example, connecting to a switch or hub). That port will then configure itself to the correct configuration. This feature also eliminates the need to worry about crossover cables, as Auto Uplink will accommodate either type of cable to make the right connection.
d. Connect the power adapter to the modem and plug it in to a power outlet. Verify the
following:
The power light is lit after turning on the modem.
Connecting the Modem to the Internet 3-7
Reference Manual for the Model DG632 ADSL Modem Router
The ADSL link light is solid green, indicating a link has been established to the ADSL network.
e. Now, turn on your computer. If software usually logs you in to your Internet connection,
do not run that software or cancel it if it starts automatically.
or
3. LOG IN TO THE DG632.
The Ethernet or USB light is lit for the connected computer.
Note: Your computer needs to be configured for DHCP. For instructions on configuring for DHCP, please see Appendix C in the Reference Manual on the ADSL Modem Router Resource CD.
a. Connect to the modem by typing http://192.168.0.1 in the address field of Internet
®
Explorer or Netscape
Figure 3-7: Log in to the modem
Navigator.
A login window opens as shown below:
Figure 3-8: Login window
b.
When prompted, enter admin for the user name and password for the password, both in lower case letters. After logging in, you will see the menu below.
Figure 3-9: Setup Wizard
3-8 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router
4.
CONNECT TO THE INTERNET
The modem is now properly attached to your network. You are now ready to configure your modem to connect to the Internet. There are two ways you can configure your modem to connect to the Internet:
a. Let the DG632 auto-detect the type of Internet connection you have and configure it.
b. Manually choose which type of Internet connection you have and configure it.
These options are described below. In either case, unless your ISP automatically assigns your configuration automatically via DHCP, you need the configuration parameters from your ISP you recorded in “Record Your Internet Connection Information” on page 3-4.

Auto-Detecting Your Internet Connection Type

The Web Configuration Manager built in to the modem contains a Setup Wizard that can automatically determine your network connection type.
1. If your modem has not yet been configured, the Setup Wizard shown in Figure 3-9 should
launch automatically.
Note: If instead of the Setup Wizard menu, the main menu of the modem’s Configuration Manager appears, click the Setup Wizard link in the upper left to bring up this menu.
2. You must select a country and language.
3. Select Yes to allow the modem to automatically determine your connection.
4. Click Next.
The Setup Wizard will now check for the following connection types:
Connecting the Modem to the Internet 3-9
Reference Manual for the Model DG632 ADSL Modem Router
Dynamic IP assignment
A login protocol such as PPPoE or PPPoA
Next, the Setup Wizard will report which connection type it has discovered, and then display the appropriate configuration page. If the Setup Wizard finds no connection, you will be prompted to check the physical connection between your modem and the ADSL line. When the connection is properly made, the modem’s Internet LED should be on.
5. The ADSL settings for the multiplexing method and VPI/VCI will update with the preset
defaults. The multiplexing method preset default settings will usually work. Only change the multiplexing method if you are sure your ISP requires Virtual Path Identifier (VPI) or Virtual Channel Identifier (VCI) settings that are different from the default values.
Incorrect VPI or VCI settings will prevent you from connecting to the Internet. To change these settings, click the ADSL Settings link on the main menu.
The procedures for filling in the configuration page for each type of connection follow below.

Wizard-Detected PPPoE Login Account Setup

If the Setup Wizard determines that your Internet service account uses a login protocol such as PPP over Ethernet (PPPoE), you will be directed to the PPPoE page shown in Figure 3-10:
Figure 3-10: Setup Wizard menu for PPPoE login accounts
Enter the PPPoE login user name and password.
3-10 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router

Wizard-Detected PPPoA Login Account Setup

If the Setup Wizard determines that your Internet service account uses a login protocol such as PPP over ATM (PPPoA), you will be directed to the PPPoA page shown in Figure 3-10 below:
Figure 3-11: Setup Wizard menu for PPPoA login accounts
Enter your login user name and password. These fields are case sensitive.

Wizard-Detected Dynamic IP Account Setup

If the Setup Wizard determines that your Internet service account uses Dynamic IP assignment, you will be directed to the page shown in Figure 3-12 below:
Figure 3-12: Setup Wizard menu for Dynamic IP address
Click Apply to set Dynamic IP as the connection method.
6. Click the Test button to test your Internet connection. If the NETGEAR Web site does not
appear within one minute, refer to Chapter 7, “Troubleshooting”.
Connecting the Modem to the Internet 3-11
Reference Manual for the Model DG632 ADSL Modem Router

Testing Your Internet Connection

After completing the Internet connection configuration, your can test your Internet connection. Log in to the modem, then, from the Basic Settings link in the Setup menu, click the Test button. If the NETGEAR Web site does not appear within one minute, refer to Chapter 7,
“Troubleshooting”.
Your modem is now configured to provide Internet access for your network. Your modem automatically connects to the Internet when one of your computers requires access. It is not necessary to run a dialer or login application such as Dial-Up Networking or Enternet to connect, log in, or disconnect. These functions are performed by the modem as needed.
To access the Internet from any computer connected to your modem, launch a browser such as Microsoft Internet Explorer or Netscape Navigator. You should see the modem’s Internet LED blink, indicating communication to the ISP. The browser should begin to display a Web page.
The following chapters describe how to configure the Advanced features of your modem, and how to troubleshoot problems that may occur.

Connecting Your Computer to the DG632 USB Port Option

You can connect your PC to the USB 1.1 modem port of the DG632. To connect your computer to the modem via USB involves installing the USB driver:
Note: The USB connection option is only available for Windows PCs. Also, Windows
95 does not support USB without special operating system upgrades and patches.
Follow these steps to install the USB driver.
1. Insert the CD which came with your modem into the CD drive of your computer.
2. Click the Install USB Driver button.
Be sure the DG632 is not plugged in before installing the software on your PC.
3-12 Connecting the Modem to the Internet
Reference Manual for the Model DG632 ADSL Modem Router
Click Ok to run the software installation utility.
3.
4. Click Next and follow the prompts to complete the installation of the USB driver.
5. Now, connect the USB cable to your modem and plug in the AC power for the modem.
6. Use the USB cable to connect your computer to the modem.
The found new hardware Windows installation wizard will prompt you to complete the installation and inform you when the PC is ready to use the USB connection.
You have now finished connecting your DG632.
Connecting the Modem to the Internet 3-13
Reference Manual for the Model DG632 ADSL Modem Router
3-14 Connecting the Modem to the Internet
Chapter 4
Maintaining Your
DG632 ADSL Modem Router
This chapter describes how to perform maintenance tasks with your DG632 ADSL Modem Router.

Changing the Mode of Operation

The DG632 ADSL Modem Router can operate in the following modes:
Modem: In modem mode, you can connect a single computer to the Internet.
Router: In router mode, you can connect more than one computer to the Internet and take
advantage of advanced management and security features.
The modem includes a limited feature router to make the process of configuring your connection easier and more secure. You can change the operation of the modem from Modem Device Mode to Router Device Mode.
In Modem Device Mode, the modem operates like a DSL modem, passing all the Internet communications directly to your computer where you must then configure your settings and logon settings as needed.
In Router Device Mode, the modem provides limited router functionality which allows you to have the modem perform any logon steps your ISP may require. In this mode, it is also easier to configure your computer by taking advantage of the automatic configuration capabilities of DHCP which the router provides.
Follow these steps to change the DG632 mode of operation.
Note: If you change the modem from Router Mode to Modem Mode, your computer
must configured with a static IP address of 192.168.0.2-192.168.0.254, a Subnet Mask of 255.255.255.0, and a Gateway Address of 192.168.0.1 to be able to connect to the modem’s built-in configuration pages.
Maintaining Your DG632 ADSL Modem Router 4-1
Reference Manual for the Model DG632 ADSL Modem Router
Turn on the modem and wait at least ten seconds for initialization to complete.
1.
2. Reboot your computer to obtain DHCP configuration from the modem.
3. Launch your web browser, and click your browser’s Stop button.
4. In the Address or Location box of your browser, type http://192.168.0.1 and click Enter.
A login window opens as shown in Figure 4-1 below:.
Figure 4-1. Modem Login window
5.
Type admin in the User Name box, password in the Password box, and click OK.
6. When the Basic Settings screen appears click Device Mode to this menu.
Figure 4-2. Device Type selection window
7.
Select the mode.
8. Click Apply to save your changes.
4-2 Maintaining Your DG632 ADSL Modem Router
Reference Manual for the Model DG632 ADSL Modem Router
After changing the mode, the main menu changes, showing the features of the mode selected.
Router Mode Menu
Figure 4-3. Device Mode main menu options
Modem Mode Menu

Changing the Password of Your DG632 ADSL Modem Router

For security reasons, the modem has its own user name and password. Also, after a period of inactivity for a set length of time, the administrator login will automatically disconnect. When prompted, enter admin for the modem User Name and password for the modem Password. You can use procedures below to change the modem's password and the amount of time for the administrator’s login timeout.
Note: The user name and password are not the same as any user name or password your may use
to log in to your Internet connection.
NETGEAR recommends that you change this password to a more secure password. The ideal password should contain no dictionary words from any language, and should be a mixture of both upper and lower case letters, numbers, and symbols. Your password can be up to 30 characters.
Maintaining Your DG632 ADSL Modem Router 4-3
Reference Manual for the Model DG632 ADSL Modem Router

How to Change the Built-In Password

1. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever Password and LAN address you have chosen for the modem.
Figure 4-4: Log in to the modem
2.
From the Main Menu of the browser interface, under the Maintenance heading, select Set Password to bring up the menu shown in Figure 4-5.
Figure 4-5: Set Password menu
3.
To change the password, first enter the old password, and then enter the new password twice.
4. Click Apply to save your changes.
Note: After changing the password, you will be required to log in again to continue the
configuration. If you have backed up the modem settings previously, you should do a new backup so that the saved settings file includes the new password.

Changing the Administrator Login Timeout

For security, the administrator's login to the modem configuration will timeout after a period of inactivity. To change the login timeout period:
1. In the Set Password menu, type a number in ‘Administrator login times out’ field. The
suggested default value is 5 minutes.
4-4 Maintaining Your DG632 ADSL Modem Router
Reference Manual for the Model DG632 ADSL Modem Router
Click Apply to save your changes or click Cancel to keep the current period.
2.

Backing Up, Restoring, or Erasing Your Settings

The configuration settings of the DG632 modem router are stored in a configuration file in the modem. This file can be backed up to your computer, restored, or reverted to factory default settings. The procedures below explain how to do these tasks.

How to Back Up the Configuration to a File

1. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever User Name, Password and LAN address you have chosen for the modem.
2. From the Maintenance heading of the Main Menu, select the Backup Settings menu as seen in
Figure 4-6.
Figure 4-6: Backup Settings menu
3.
Click Backup to save a copy of the current settings.
4. Store the .cfg file on a computer on your network.
Maintaining Your DG632 ADSL Modem Router 4-5
Reference Manual for the Model DG632 ADSL Modem Router

How to Restore the Configuration from a File

1. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever User Name, Password and LAN address you have chosen for the modem.
2. From the Maintenance heading of the Main Menu, select the Settings Backup menu as seen in
Figure 4-6.
3. Enter the full path to the file on your network or click the Browse button to locate the file.
4. When you have located the .cfg file, click the Restore button to upload the file to the modem.
5. The modem will then reboot automatically.

How to Erase the Configuration

It is sometimes desirable to restore the modem to the factory default settings. This can be done by using the Erase function.
1. To erase the configuration, from the Maintenance menu Settings Backup link, click the Erase
button on the screen.
2. The modem will then reboot automatically.
After an erase, the modem's password will be password, the LAN IP address will be
192.168.0.1, and the modem's DHCP client will be enabled.
Note: To restore the factory default configuration settings without knowing the login password or
IP address, you must use the Default Reset button on the rear panel of the modem. See “DG632
Rear Panel“ on page 2-7.

Upgrading the Modem’s Firmware

The software of the DG632 modem router is stored in FLASH memory, and can be upgraded as new software is released by NETGEAR.
Upgrade files can be downloaded from NETGEAR's Web site. If the upgrade file is compressed (.ZIP file), you must first extract the binary (.BIN or .IMG) file before uploading it to the modem.
4-6 Maintaining Your DG632 ADSL Modem Router
Reference Manual for the Model DG632 ADSL Modem Router

How to Upgrade the Modem Firmware

Note: NETGEAR recommends that you back up your configuration before doing a firmware
upgrade. After the upgrade is complete, you may need to restore your configuration settings.
1. Download and unzip the new software file from NETGEAR.
The Web browser used to upload new firmware into the modem must support HTTP uploads. NETGEAR recommends using Microsoft Internet Explorer 5.0 or above, or Netscape Navigator 4.7 or above.
2. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever User Name, Password and LAN address you have chosen for the modem.
3. From the Main Menu of the browser interface, under the Maintenance heading, select the
Modem Upgrade heading to display this menu.
Figure 4-7: Modem Upgrade menu
4.
In the Modem Upgrade menu, click the Browse to locate the binary (.BIN or .IMG) upgrade file.
5. Click Upload.
Note: When uploading software to the modem, it is important not to interrupt the Web
browser by closing the window, clicking a link, or loading a new page. If the browser is interrupted, it may corrupt the software. When the upload is complete, your modem will automatically restart. The upgrade process will typically take about one minute. In some cases, you may need to clear the configuration and reconfigure the modem after upgrading.
Maintaining Your DG632 ADSL Modem Router 4-7
Reference Manual for the Model DG632 ADSL Modem Router
4-8 Maintaining Your DG632 ADSL Modem Router
This chapter describes how to use the modem features of the DG632 ADSL Modem Router.
Figure 5-1: Modem Mode main menu
Chapter 5
Using Modem Mode

Modem Mode Basic Settings

You can manually configure your modem using the menu above, or you can allow the Setup Wizard to determine your configuration as described in the previous section.

Manually Configuring Basic Settings

It is best to start the manual configuration from the Setup Wizard:
1. Select your country.
2. Select No to manually configure your modem connection.
3. Click Next.
4. Manually configure the modem in the Basic Settings menu.
Using Modem Mode 5-1
Reference Manual for the Model DG632 ADSL Modem Router
Follow the instructions below according to the encapsulation method and whether your
5.
Internet connection requires a login. The following methods are available:
Internet Connection Requires Login and Uses PPPoE
Internet Connection Requires Login and Uses PPPoA
Internet Connection Does Not Require a Login
6. Usually the default ADSL Settings work fine for most ISPs and you can skip this step. If you
have any problems with your connection, check the ADSL Settings. See “ADSL Settings“ on
page 5-4 for more details.

Internet Connection Requires Login and Uses PPPoE

1. If your Internet connection does require login, select Yes and fill in the settings according to
the instructions below.
Note: You will no longer need to launch the ISP’s login program on your computer in order to access the Internet. When you start an Internet application, your modem automatically logs you in.
2. Choose PPPoE for the encapsulation method your ISP uses.
3. Enter the login name (frequently the email address your ISP provided), password, and service
name (if required).
4. If you want to change the login timeout, enter a new value in minutes. This determines how
long the modem keeps the Internet connection active after there is no Internet activity from the LAN. Entering an Idle Timeout value of zero means never log out.
5. The DNS server is used to look up site addresses based on their names.
Select “Get Automatically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
Select “Use These DNS Servers” if your ISP gave you one or two DNS addresses. Type the primary and secondary addresses.

Internet Connection Requires Login and Uses PPPoA

1. If your Internet connection does require login, select Yes and fill in the settings according to
the instructions below.
5-2 Using Modem Mode
Reference Manual for the Model DG632 ADSL Modem Router
Note: You will no longer need to launch the ISP’s login program on your computer in order to access the Internet. When you start an Internet application, your modem automatically logs you in.
2. Choose PPPoA for the encapsulation method your ISP uses.
3. Enter the login name (frequently the email address your ISP provided), and password.
4. If you want to change the login timeout, enter a new value in minutes. This determines how
long the modem keeps the Internet connection active after there is no Internet activity from the LAN. Entering an Idle Timeout value of zero means never log out.
5. Internet IP Address:
Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign these addresses.
Select “Use Static IP Address” if your ISP has assigned you a permanent, fixed (static) IP address. Enter the IP address that your ISP assigned.
6. The DNS server is used to look up site addresses based on their names.
Select “Get Automatically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
Select “Use These DNS Servers” if your ISP has assigned you DNS server addresses. Enter the Primary and Secondary DNS server addresses that your ISP provided.

Internet Connection Does Not Require A Login

1. If your Internet connection does not require a login, select No and fill in the settings according
to the instructions below.
2. Enter your Account Name (may also be called Host Name) and Domain Name.
These parameters may be necessary to access your ISP’s mail or news servers.
3. Internet IP Address:
Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign these addresses.
Select “Use Static IP Address” if your ISP has assigned you a permanent, fixed (static) IP address. Enter the IP address that your ISP assigned. Also enter the IP Subnet Mask and the Gateway IP Address. The gateway is the ISP’s modem to which your modem will connect.
4. Domain Name Server (DNS) Address:
Using Modem Mode 5-3
Reference Manual for the Model DG632 ADSL Modem Router
Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
If you know that your ISP does not automatically transmit DNS addresses to the modem during login, select “Use these DNS servers” and enter the IP address of your ISP’s Primary DNS Server. If a Secondary DNS Server address is available, enter it also.
A DNS server is a host on the Internet that translates Internet names (such as www.netgear.com) to numeric IP addresses. Typically your ISP transfers the IP address of one or two DNS servers to your modem during login. If the ISP does not transfer an address, you must obtain it from the ISP and enter it manually here.
5. Click Apply to save your settings.
6. Click the Test button to test your Internet connection.
If the NETGEAR Web site does not appear within one minute, refer to Chapter 7,
“Troubleshooting.

ADSL Settings

The default settings of your DG632 ADSL Modem Router will work fine for most ISPs. However, some ISPs use a specific Multiplexing Method or a Virtual Circuit Number for either the Virtual Path Identifier (VPI) or Virtual Channel Identifier (VCI).
Note: The correct country must be selected from the Setup Wizard’s first page for the default
ADSL Settings to work.
If your ISP provided you with a specific Multiplexing Method or VPI/VCI number, then fill in the following:
1. Select the ADSL Settings link from the main menu.
2. For the Multiplexing Method, select LLC-based or VC-based.
3. Type a number between 0 and 255 for the VPI. The default is 8.
4. Type a number between 1 and 65535 for the VCI. The default is 35.
5. Click Apply.

Modem Mode Network Management Information

The DG632 provides a variety of status and usage information which is discussed below.
5-4 Using Modem Mode
Reference Manual for the Model DG632 ADSL Modem Router

Viewing Modem Status and Usage Statistics

From the Main Menu, under Maintenance, select Modem Status to view the screen in Figure 5-2.
Figure 5-2: Modem Status screen
The Modem Status menu provides status and usage information, as described in the following table.
Table 5-1. Menu 3.2 - Modem Status Fields
Field Description
Account Name The Host Name assigned to the modem in the Basic Settings menu.
Firmware Version Displays the modem firmware version.
ADSL Port These parameters apply to the Internet (ADSL) port of the modem.
MAC Address Displays the Ethernet MAC address being used by the Internet (ADSL)
port of the modem.
IP Address Displays the IP address being used by the Internet (ADSL) port of the
modem. If no address is shown, the modem cannot connect to the Internet.
Using Modem Mode 5-5
Reference Manual for the Model DG632 ADSL Modem Router
Table 5-1. Menu 3.2 - Modem Status Fields
Field Description
DHCP If None, the modem will use a fixed IP address on the ADSL.
If Client, the modem will obtain an IP address dynamically from the ISP
IP Subnet Mask Displays the IP Subnet Mask being used by the Internet (ADSL) port of
the modem.
Domain Name Server (DNS) Displays the DNS Server IP addresses being used by the modem. These
addresses are usually obtained dynamically from the ISP.
LAN Port These parameters apply to the Local (ADSL) port of the modem.
MAC Address Displays the Ethernet MAC address of the Local (LAN) port.
IP Address This field displays the IP address being used by the Local (LAN) port of
the modem. The default is 192.168.0.1
DHCP If OFF, the modem will not assign IP addresses to PCs on the LAN.
If ON, the modem will assign IP addresses to PCs on the LAN.
IP Subnet Mask This field displays the IP Subnet Mask being used by the Local (LAN) port
of the modem. The default is 255.255.255.0.
Modem These parameters apply to the Local (WAN) port of the modem.
ADSL Firmware Version The version of the firmware.
Router Status The connection status of the modem.
Connect Mode This field displays the protocol used to connect to your service provider.
When the ADSL link comes up, the connection will be either “Fast” or “Interleaved”, depending on the way the telephone company has configured its equipment.
Downstream Speed The speed at which the modem is receiving data from the ADSL line.
Upstream Speed The speed at which the modem is transmitting data to the ADSL line.
VPI The Virtual Path Identifier setting.
VCI The Virtual Channel Identifier setting.
5-6 Using Modem Mode
Reference Manual for the Model DG632 ADSL Modem Router
Click the Show Statistics button to display modem usage statistics, as shown in Figure 5-2 below:
Figure 5-3: Modem Statistics screen
This screen shows the following statistics:.
Table 5-1. Statistics Fields
Field Description
WAN, LAN, or Serial Port
Status The link status of the port.
TxPkts The number of packets transmitted on this port since reset or manual clear.
RxPkts The number of packets received on this port since reset or manual clear.
Collisions The number of collisions on this port since reset or manual clear.
Tx B/s The current line utilization—percentage of current bandwidth used on this port.
Rx B/s The average line utilization for this port.
Up Time The time elapsed since the last power cycle or reset.
Poll Interval Specifies the interval at which the statistics are updated in this window. Click Stop to
The statistics for the WAN (Internet), LAN (local), and Serial ports. For each port, the screen displays:
freeze the display.
Using Modem Mode 5-7
Reference Manual for the Model DG632 ADSL Modem Router
5-8 Using Modem Mode
Chapter 6
Using Router Mode
This chapter describes how to use the basic router features of the DG632 ADSL Modem Router.
Figure 6-1: Router Mode main menu

Router Mode Basic Settings

You can manually configure your modem using the menu above, or you can allow the Setup Wizard to determine your configuration as described in the previous section.
Using Router Mode 6-1
Reference Manual for the Model DG632 ADSL Modem Router
ISP Does Not Require Login
ISP Does Require Login
Figure 6-2: Basic Settings menu

Manually Configuring Basic Settings

It is best to start the manual configuration from the Setup Wizard:
1. Select your country.
2. Select No to manually configure your modem connection.
3. Click Next.
4. Manually configure the modem in the Basic Settings menu shown in Figure 6-2.
6-2 Using Router Mode
Reference Manual for the Model DG632 ADSL Modem Router
Follow the instructions below according to the encapsulation method and whether your
5.
Internet connection requires a login. The following methods are available:
Internet Connection Requires Login and Uses PPPoE
Internet Connection Requires Login and Uses PPPoA
Internet Connection Does Not Require a Login
6. Usually the default ADSL Settings work fine for most ISPs and you can skip this step. If you
have any problems with your connection, check the ADSL Settings. See “ADSL Settings“ on
page -5 for more details.

Internet Connection Requires Login and Uses PPPoE

1. If your Internet connection does require login, select Yes and fill in the settings according to
the instructions below.
Note: You will no longer need to launch the ISP’s login program on your computer in order to access the Internet. When you start an Internet application, your modem automatically logs you in.
2. Choose PPPoE for the encapsulation method your ISP uses.
3. Enter the login name (frequently the email address your ISP provided), password, and service
name (if required).
4. If you want to change the login timeout, enter a new value in minutes. This determines how
long the modem keeps the Internet connection active after there is no Internet activity from the LAN. Entering an Idle Timeout value of zero means never log out.
5. The DNS server is used to look up site addresses based on their names.
Select “Get Automatically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
Select “Use These DNS Servers” if your ISP gave you one or two DNS addresses. Type the primary and secondary addresses.

Internet Connection Requires Login and Uses PPPoA

1. If your Internet connection does require login, select Yes and fill in the settings according to
the instructions below.
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Note: You will no longer need to launch the ISP’s login program on your computer in order to access the Internet. When you start an Internet application, your modem automatically logs you in.
2. Choose PPPoA for the encapsulation method your ISP uses.
3. Enter the login name (frequently the email address your ISP provided), and password.
4. If you want to change the login timeout, enter a new value in minutes. This determines how
long the modem keeps the Internet connection active after there is no Internet activity from the LAN. Entering an Idle Timeout value of zero means never log out.
5. Internet IP Address:
Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign these addresses.
Select “Use Static IP Address” if your ISP has assigned you a permanent, fixed (static) IP address. Enter the IP address that your ISP assigned.
6. The DNS server is used to look up site addresses based on their names.
Select “Get Automatically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
Select “Use These DNS Servers” if your ISP has assigned you DNS server addresses. Enter the Primary and Secondary DNS server addresses that your ISP provided.

Internet Connection Does Not Require A Login

1. If your Internet connection does not require a login, select No and fill in the settings according
to the instructions below.
2. Enter your Account Name (may also be called Host Name) and Domain Name.
These parameters may be necessary to access your ISP’s mail or news servers.
3. Internet IP Address:
Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign these addresses.
Select “Use Static IP Address” if your ISP has assigned you a permanent, fixed (static) IP address. Enter the IP address that your ISP assigned. Also enter the IP Subnet Mask and the Gateway IP Address. The gateway is the ISP’s modem to which your modem will connect.
4. Domain Name Server (DNS) Address:
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Select “Get Dynamically from ISP” if your ISP uses DHCP to assign your IP address. Your ISP will automatically assign this address.
If you know that your ISP does not automatically transmit DNS addresses to the modem during login, select “Use these DNS servers” and enter the IP address of your ISP’s Primary DNS Server. If a Secondary DNS Server address is available, enter it also.
A DNS server is a host on the Internet that translates Internet names (such as www.netgear.com) to numeric IP addresses. Typically your ISP transfers the IP address of one or two DNS servers to your modem during login. If the ISP does not transfer an address, you must obtain it from the ISP and enter it manually here.
5. Click Apply to save your settings.
6. Click the Test button to test your Internet connection.
If the NETGEAR Web site does not appear within one minute, refer to Chapter 7,
“Troubleshooting.

ADSL Settings

The default settings of your DG632 ADSL Modem Router will work fine for most ISPs. However, some ISPs use a specific Multiplexing Method or a Virtual Circuit Number for either the Virtual Path Identifier (VPI) or Virtual Channel Identifier (VCI).
Note: The correct country must be selected from the Setup Wizard’s first page for the default
ADSL Settings to work.
If your ISP provided you with a specific Multiplexing Method or VPI/VCI number, then fill in the following:
1. Select the ADSL Settings link from the main menu.
2. For the Multiplexing Method, select LLC-based or VC-based.
3. Type a number between 0 and 255 for the VPI. The default is 8.
4. Type a number between 1 and 65535 for the VCI. The default is 35.
5. Click Apply.

Router Mode Network Management Information

The DG632 provides a variety of status and usage information which is discussed below.
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Viewing Router Status and Usage Statistics

From the Main Menu, under Maintenance, select Router Status to view the screen in Figure 6-3.
Figure 6-3: Router Status screen
The Router Status menu provides status and usage information, as described in the following table.
Table 6-1. Menu 3.2 - Modem Status Fields
Field Description
Account Name The Host Name assigned to the modem in the Basic Settings menu.
Firmware Version Displays the modem firmware version.
ADSL Port These parameters apply to the Internet (ADSL) port of the modem.
MAC Address Displays the Ethernet MAC address being used by the Internet (ADSL)
port of the modem.
IP Address Displays the IP address being used by the Internet (ADSL) port of the
modem. If no address is shown, the modem cannot connect to the Internet.
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Table 6-1. Menu 3.2 - Modem Status Fields
Field Description
DHCP If None, the modem will use a fixed IP address on the ADSL.
If Client, the modem will obtain an IP address dynamically from the ISP
IP Subnet Mask Displays the IP Subnet Mask being used by the Internet (ADSL) port of
the modem.
Domain Name Server (DNS) Displays the DNS Server IP addresses being used by the modem. These
addresses are usually obtained dynamically from the ISP.
LAN Port These parameters apply to the Local (ADSL) port of the modem.
MAC Address Displays the Ethernet MAC address of the Local (LAN) port.
IP Address This field displays the IP address being used by the Local (LAN) port of
the modem. The default is 192.168.0.1
DHCP If OFF, the modem will not assign IP addresses to PCs on the LAN.
If ON, the modem will assign IP addresses to PCs on the LAN.
IP Subnet Mask This field displays the IP Subnet Mask being used by the Local (LAN) port
of the modem. The default is 255.255.255.0.
Router These parameters apply to the Local (WAN) port of the modem.
ADSL Firmware Version The version of the firmware.
Router Status The connection status of the modem.
Connect Mode This field displays the protocol used to connect to your service provider.
When the ADSL link comes up, the connection will be either “Fast” or “Interleaved”, depending on the way the telephone company has configured its equipment.
Downstream Speed The speed at which the modem is receiving data from the ADSL line.
Upstream Speed The speed at which the modem is transmitting data to the ADSL line.
VPI The Virtual Path Identifier setting.
VCI The Virtual Channel Identifier setting.
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Click the Show Statistics button to display modem usage statistics, as shown in Figure 6-3 below:
Figure 6-4: Router Statistics screen
This screen shows the following statistics:.
Table 6-1. Statistics Fields
Field Description
WAN, LAN, or Serial Port
Status The link status of the port.
TxPkts The number of packets transmitted on this port since reset or manual clear.
RxPkts The number of packets received on this port since reset or manual clear.
Collisions The number of collisions on this port since reset or manual clear.
Tx B/s The current line utilization—percentage of current bandwidth used on this port.
Rx B/s The average line utilization for this port.
Up Time The time elapsed since the last power cycle or reset.
Poll Interval Specifies the interval at which the statistics are updated in this window. Click Stop to
The statistics for the WAN (Internet), LAN (local), and Serial ports. For each port, the screen displays:
freeze the display.
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Click the Connection Status button to display router connection status, as shown in Figure 6-5 and
Figure 6-6.
Figure 6-5: Connection Status screen for Dynamic IP
Clicking the Renew button updates the status information.
This screen shows the following statistics:
Table 6-1. Connection Status Fields for Dynamic IP
Field Description
IP Address The IP Address assigned to the WAN port by the ADSL Internet Service Provider.
Subnet Mask Then Network Mask assigned to the WAN port by the ADSL Internet Service Provider.
Default Gateway Then default gateway modem assigned to the WAN port by the ADSL Internet Service
Provider.
DHCP Server The DHCP server’s IP address.
DNS Server The DNS server’s IP address.
Lease Obtained Date and time the lease was obtained.
Lease Expires Date and time the lease expires.
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An alternate view of the Connection Status screen is shown in Figure 6-6 below:
Figure 6-6: Connection Status screen for PPPoA
Clicking the Renew button updates the status information.
This screen shows the following statistics:
Table 6-1. Connection Status Fields for PPPoA
Field Description
Connection Time The time elapsed since the last connection to the Internet via the ADSL port.
Connection Method The method the ADSL port acquired its TCP/IP configuration.
IP Address The IP Address assigned to the WAN port by the ADSL Internet Service Provider.
Network Mask Then Network Mask assigned to the WAN port by the ADSL Internet Service Provider.
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Viewing, Selecting, and Saving Router Mode Logged Information

The modem will log security-related events such as denied incoming service requests, hacker probes, and administrator logins.
Here is an example of the logs file.
Figure 6-7: Security Logs menu
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Log entries are described in Table 6-1 below:
Table 6-1. Security Log entry descriptions
Field Description
Description or Action The type of event and what action was taken if any.
Source IP The IP address of the initiating device for this log entry.
Source port and interface The service port number of the initiating device, and whether it
originated from the LAN or WAN
Destination The name or IP address of the destination device or Web site.
Destination port and interface
The service port number of the destination device, and whether it’s on the LAN or WAN.
Log action buttons are described in Table 6-2
Table 6-2. Security Log action buttons
Field Description
Refresh Refresh the log screen.
Clear Log Clear the log entries.
Remove
Remove a logging destination from the list.
(logging destination)
Selecting What Information to Log
Besides the standard information listed above, you can choose to log additional information. Those optional selections are as follows:
Attempted access to blocked site
Connections to the Web-based interface of the modem
Modem operation (start up, get time, etc.)
Known DoS attacks and Port Scans
Saving Log Files on a Server
You can choose to write the logs to a computer running a syslog program. To activate this feature, enter the IP address of the server where the Syslog file will be written.
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Router Mode Diagnostic Utilities and Rebooting

The DG632 modem router has a diagnostics feature. You can use the diagnostics menu to perform the following functions from the modem:
Ping an IP Address to test connectivity to see if you can reach a remote host.
Perform a DNS Lookup to test if an Internet name resolves to an IP address to verify that the DNS server configuration is working.
Display the Routing Table to identify what other modems the modem is communicating with.
Reboot the modem to enable new network configurations to take effect or to clear problems with the modem’s network connection.
From the Main Menu of the browser interface, under the Maintenance heading, select the Modem Diagnostics heading to display the menu shown in Figure 6-8.
Figure 6-8: Diagnostics menu
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Firewall Services

Services are functions performed by server computers at the request of client computers. For example, Web servers serve Web pages, time servers serve time and date information, and game hosts serve data about other players’ moves. When a computer on the Internet sends a request for service to a server computer, the requested service is identified by a service or port number. This number appears as the destination port number in the transmitted IP packets. For example, a packet that is sent with destination port number 80 is an HTTP (Web server) request.
The service numbers for many common protocols are defined by the Internet Engineering Task Force (IETF) and published in RFC1700, “Assigned Numbers.” Service numbers for other applications are typically chosen from the range 1024 to 65535 by the authors of the application.
Although the DG632 already holds a list of many service port numbers, you are not limited to these choices. Use the procedure below to create your own service definitions.

How to Define Services

1. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever Password and LAN address you have chosen for the modem.
2. Select the Services link of the Security menu to display the Services menu shown in
Figure 6-9:
Figure 6-9: Services menu
To create a new Service, click the Add Custom Service button.
To edit an existing Service, select its button on the left side of the table and click Edit
Service.
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To delete an existing Service, select its button on the left side of the table and click Delete
Service.
3. Use the page shown below to define or edit a service.
Figure 6-10: Add Services menu
4.
Click Apply to save your changes.

Firewall Rules

Firewall rules are used to block or allow specific traffic passing through from one side to the other. Inbound rules (WAN to LAN) restrict access by outsiders to private resources, selectively allowing only specific outside users to access specific resources. Outbound rules (LAN to WAN) determine what outside resources local users can have access to.
A firewall has two default rules, one for inbound traffic and one for outbound. The default rules of the DG632 are:
Inbound: Block all access from outside except responses to requests from the LAN side.
Outbound: Allow all access from the LAN side to the outside.
You can define additional rules that will specify exceptions to the default rules. By adding custom rules, you can block or allow access based on the service or application, source or destination IP addresses, and time of day. You can also choose to log traffic that matches or does not match the rule you have defined.
To access the rules configuration of the DG632, click the Firewall Rules link on the main menu, then click Add for either an Outbound or Inbound Service.
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Figure 6-11: Rules menu
To edit an existing rule, select its button on the left side of the table and click Edit.
To delete an existing rule, select its button on the left side of the table and click Delete.

Inbound Rules (Port Forwarding)

Because the DG632 uses Network Address Translation (NAT), your network presents only one IP address to the Internet, and outside users cannot directly address any of your local computers. However, by defining an inbound rule you can make a local server (for example, a Web server or game server) visible and available to the Internet. The rule tells the modem to direct inbound traffic for a particular service to one local server based on the destination port number. This is also known as port forwarding.
Note: Some residential broadband ISP accounts do not allow you to run any server processes (such as a Web or FTP server) from your location. Your ISP may periodically check for servers and may suspend your account if it discovers any active services at your location. If you are unsure, refer to the Acceptable Use Policy of your ISP.
Remember that allowing inbound services opens holes in your firewall. Only enable those ports that are necessary for your network. Following are two application examples of inbound rules:
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Inbound Rule Example: A Local Public Web Server
If you host a public Web server on your local network, you can define a rule to allow inbound Web (HTTP) requests to the IP address of your Web server. This rule is shown in Figure 6-12:
Figure 6-12: Rule example: A Local Public Web Server
The parameters are:
1. LAN Server IP Address
Enter the IP address of the computer or server on your LAN which will receive the inbound traffic covered by this rule.
2. Category
From this list, select the category of application or service to be allowed.
3. Services
From this list, select the specific service or application. The list already displays many common services, but you are not limited to these choices. Use the Services menu to add any additional services or applications that do not already appear.
4. Click Apply.
Considerations for Inbound Rules
If your external IP address is assigned dynamically by your ISP, the IP address may change periodically as the DHCP lease expires. Consider using the Dynamic DNS feature in the Advanced menus so that external users can always find your network.
If the IP address of the local server computer is assigned by DHCP, it may change when the computer is rebooted. To avoid this, use the Reserved IP address feature in the LAN IP menu to keep the computer’s IP address constant.
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Local computers must access the local server using the computer’s local LAN address (192.168.0.11 in the example in Figure 6-12 above). Attempts by local computers to access the server using the external WAN IP address will fail.

Outbound Rules (Service Blocking)

The DG632 allows you to block the use of certain Internet services by computers on your network. This is called service blocking or port filtering. You can define an outbound rule to block Internet access from a local computer based on:
IP address of the local computer (source address)
Type of service being requested (service port number)
Following is an application example of outbound rules:
Outbound Rule Example: Doom
If you want to block usage of the game Doom, you can create an outbound rule to block that application from any internal IP address.
Figure 6-13: Rule example: Blocking Doom
The parameters are:
1. Host IP Address
Enter the IP address of the computer on your LAN from which you would like to block traffic covered by this rule.
2. Category
From this list, select the category of application or service to be blocked.
3. Services
From this list, select the specific service or application. The list already displays many common services, but you are not limited to these choices. Use the Services menu to add any additional services or applications that do not already appear.
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Click Apply.
4.

Configuring Advanced Settings

The DG632 ADSL Modem Router provides a variety of advanced features, such as:
Setting up a Demilitarized Zone (DMZ) Server
Connecting Automatically, as Required
Disabling Port Scan and DOS Protection
Responding to a Ping on the Internet WAN Port
•MTU Size
The flexibility of configuring your LAN TCP/IP settings
Using the Router as a DHCP Server
Configuring Static Routes
These features are discussed below.

Setting Up A Default DMZ Server

The Default DMZ Server feature is helpful when using some online games and videoconferencing applications that are incompatible with NAT. The modem is programmed to recognize some of these applications and to work properly with them, but there are other applications that may not function well. In some cases, one local computer can run the application properly if that computer’s IP address is entered as the Default DMZ Server.
Note: For security reasons, you should avoid using the Default DMZ Server feature.
When a computer is designated as the Default DMZ Server, it loses much of the protection of the firewall, and is exposed to many exploits from the Internet. If compromised, the computer can be used to attack your network.
Incoming traffic from the Internet is normally discarded by the modem unless the traffic is a response to one of your local computers or a service that you have configured in the Ports menu. Instead of discarding this traffic, you can have it forwarded to one computer on your network. This computer is called the Default DMZ Server.
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How to Configure a Default DMZ Server
To assign a computer or server to be a Default DMZ server, follow these steps:
1. Log in to the modem at its default LAN address of http://192.168.0.1 with its default User
Name of admin, default password of password, or using whatever Password and LAN address you have chosen for the modem.
2. From the Main Menu, under Advanced, click the WAN Setup link to view the page shown in
Figure 6-14
Figure 6-14: WAN Setup Page
3.
Click Default DMZ Server.
4. Type the IP address for that server.
5. Click Apply to save your changes.

Connect Automatically, as Required

Normally, this option should be Enabled, so that an Internet connection will be made automatically, whenever Internet-bound traffic is detected. If this causes high connection costs, you can disable this setting.
If disabled, you must connect manually, using the sub-screen accessed from the "Connection Status" button on the Status screen.
If you have an "Always on" connection, this setting has no effect.
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Disable Port Scan and DOS Protection

The Firewall protects your LAN against Port Scans and Denial of Service (DOS) attacks. This should be disabled only in special circumstances.

Respond to Ping on Internet WAN Port

If you want the modem to respond to a 'ping' from the Internet, select the ‘Respond to Ping on Internet WAN Port’ check box. This should only be used as a diagnostic tool, since it allows your modem to be discovered. Do not select this box unless you have a specific reason to do so.

MTU Size

The normal MTU (Maximum Transmit Unit) value for most Ethernet networks is 1500 Bytes, or 1492 Bytes for PPPoE connections. For some ISPs you may need to reduce the MTU. But this is rarely required, and should not be done unless you are sure it is necessary for your ISP connection.

Configuring LAN IP Settings

The LAN IP Setup menu allows configuration of LAN IP services such as DHCP and RIP. These features can be found under the Advanced heading in the Main Menu of the browser interface.
The modem is shipped preconfigured to use private IP addresses on the LAN side, and to act as a DHCP server. The modem’s default LAN IP configuration is:
LAN IP addresses—192.168.0.1
Subnet mask—255.255.255.0
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These addresses are part of the Internet Engineering Task Force (IETF)-designated private address range for use in private networks, and should be suitable in most applications. If your network has a requirement to use a different IP addressing scheme, you can make those changes in this menu.
Figure 6-15: LAN IP Setup Menu
The LAN TCP/IP Setup parameters are:
IP Address This is the LAN IP address of the modem.
IP Subnet Mask This is the LAN Subnet Mask of the modem. Combined with the IP address, the IP Subnet Mask allows a device to know which other addresses are local to it, and which must be reached through a gateway or modem.
RIP Direction RIP (Router Information Protocol) allows a modem to exchange routing information with other routers. The RIP Direction selection controls how the Modem sends and receives RIP packets. Both is the default.
— When set to Both or Out Only, the modem will broadcast its routing table periodically.
— When set to Both or In Only, it will incorporate the RIP information that it receives.
— When set to None, it will not send any RIP packets and will ignore any RIP packets
received.
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RIP Version This controls the format and the broadcasting method of the RIP packets that the modem sends. It recognizes both formats when receiving. By default, this is set for RIP-1.
— RIP-1 is universally supported. RIP-1 is probably adequate for most networks, unless you
have an unusual network setup.
— RIP-2 carries more information. Both RIP-2B and RIP-2M send the routing data in RIP-2
format.
— RIP-2B uses subnet broadcasting.
— RIP-2M uses multicasting.
Note: If you change the LAN IP address of the modem while connected through the
browser, you will be disconnected. You must then open a new connection to the new IP address and log in again.

DHCP

By default, the modem will function as a DHCP (Dynamic Host Configuration Protocol) server, allowing it to assign IP, DNS server, and default gateway addresses to all computers connected to the modem's LAN. The assigned default gateway address is the LAN address of the router. IP addresses will be assigned to the attached PCs from a pool of addresses specified in this menu. Each pool address is tested before it is assigned to avoid duplicate addresses on the LAN.
For most applications, the default DHCP and TCP/IP settings of the router are satisfactory. See “IP
Configuration by DHCP“ on page -10 for an explanation of DHCP and information about how to
assign IP addresses for your network.
Use Router as DHCP server
If another device on your network will be the DHCP server, or if you will manually configure the network settings of all of your computers, clear the ‘Use router as DHCP server’ check box. Otherwise, leave it selected.
Specify the pool of IP addresses to be assigned by setting the Starting IP Address and Ending IP Address. These addresses should be part of the same IP address subnet as the router’s LAN IP address. Using the default addressing scheme, you should define a range between 192.168.0.2 and
192.168.0.254, although you may want to save part of the range for devices with fixed addresses.
The router will deliver the following parameters to any LAN device that requests DHCP:
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An IP Address from the range you have defined
Subnet Mask
Gateway IP Address is the router’s LAN IP address
Primary DNS Server, if you entered a Primary DNS address in the Basic Settings menu; otherwise, the router’s LAN IP address
Secondary DNS Server, if you entered a Secondary DNS address in the Basic Settings menu
Address Reservation
When you specify a reserved IP address for a computer on the LAN, that computer will always receive the same IP address each time it access the router’s DHCP server. Reserved IP addresses should be assigned to servers that require permanent IP settings.
To reserve an IP address:
1. Click the Add button.
2. In the IP Address box, type the IP address to assign to the computer or server.
Choose an IP address from the router’s LAN subnet, such as 192.168.0.x.
3. Type the MAC Address and Device Name of the computer or server.
Tip: If the computer is already present on your network, you can copy its MAC address from the Attached Devices menu and paste it here.
4. Click Apply to enter the reserved address into the table.
Note: The reserved address will not be assigned until the next time the computer contacts the router's DHCP server. Reboot the computer or access its IP configuration and force a DHCP release and renew.
To edit or delete a reserved address entry:
1. Click the button next to the reserved address you want to edit or delete.
2. Click Edit or Delete.

How to Configure LAN TCP/IP Settings

1. Log in to the router at its default LAN address of http://192.168.0.1 with its default User Name
of admin, default password of password, or using whatever User Name, Password and LAN address you have chosen for the router.
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From the Main Menu, under Advanced, click the LAN IP Setup link to view the menu, shown
2.
in Figure 6-15.
3. Enter the TCP/IP parameters.
4. Click Apply to save your changes.

Using Static Routes

Static Routes provide additional routing information to your router. Under normal circumstances, the router has adequate routing information after it has been configured for Internet access, and you do not need to configure additional static routes. You must configure static routes only for unusual cases such as multiple routers or multiple IP subnets located on your network.

Static Route Example

As an example of when a static route is needed, consider the following case:
Your primary Internet access is through a cable modem to an ISP.
You have an ISDN router on your home network for connecting to the company where
you are employed. This router’s address on your LAN is 192.168.0.100.
Your company’s network is 134.177.0.0.
When you first configured your router, two implicit static routes were created. A default route was created with your ISP as the modem, and a second static route was created to your local network for all 192.168.0.x addresses. With this configuration, if you attempt to access a device on the
134.177.0.0 network, your router will forward your request to the ISP. The ISP forwards your
request to the company where you are employed, and the request will likely be denied by the company’s firewall.
In this case you must define a static route, telling your router that 134.177.0.0 should be accessed through the ISDN router at 192.168.0.100. The static route would look like Figure 6-17.
In this example:
The Destination IP Address and IP Subnet Mask fields specify that this static route applies to all 134.177.x.x addresses.
The Modem IP Address fields specifies that all traffic for these addresses should be forwarded to the ISDN router at 192.168.0.100.
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A Metric value of 1 will work since the ISDN router is on the LAN. This represents the number of routers between your network and the destination. This is a direct connection so it is set to 1.
Private is selected only as a precautionary security measure in case RIP is activated.

How to Configure Static Routes

1. Log in to the router at its default LAN address of http://192.168.0.1 with its default User Name
of admin, default password of password, or using whatever User Name, Password and LAN address you have chosen for the router.
2. From the Main Menu of the browser interface, under Advanced, click Static Routes to view
the Static Routes menu, shown in Figure 6-16.
Figure 6-16: Static Routes Table
3.
To add or edit a Static Route:
a. Click the Edit button to open the Edit Menu, shown in Figure 6-17.
Figure 6-17: Static Route Entry and Edit Menu
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Type a route name for this static route in the Route Name box under the table.
b.
This is for identification purpose only.
c. Type the Destination IP Address of the final destination.
d. Type the IP Subnet Mask for this destination.
If the destination is a single host, type 255.255.255.255.
e. Type the Gateway IP Address, which must be a router on the same LAN segment as the
router.
f. Type a number between 2 and 15 as the Metric value.
This represents the number of routers between your network and the destination. Usually, a setting of 2 or 3 works, but if this is a direct connection, set it to 2.
g. Select Active to make this route effective.
h. Select Private if you want to limit access to the LAN only.
The static route will not be reported in RIP.
4. Click Apply to have the static route entered into the table.
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Chapter 7
Troubleshooting
This chapter gives information about troubleshooting your DG632 ADSL Modem Router. After each problem description, instructions are provided to help you diagnose and solve the problem. For the common problems listed, go to the section indicated.
Is the router on?
Have I connected the router correctly?
Go to “Basic Functioning” on page 7-1.
I can’t access the router’s configuration with my browser.
Go to “Troubleshooting the Web Configuration Interface” on page 7-2.
I’ve configured the router but I can’t access the Internet.
Go to “Troubleshooting the ISP Connection” on page 7-3.
I can’t remember the router’s configuration password.
Go to “Restoring the Default Configuration and Password” on page 7-8.
I want to clear the configuration and start over again.
Go to “Restoring the Default Configuration and Password” on page 7-8.

Basic Functioning

After you turn on power to the router, the following sequence of events should occur:
1. When power is first applied, verify that the Power LED is on (see “The Front Panel” on page
2-6 for an illustration and explanation of the LEDs).
2. After approximately 10 seconds, verify that:
a. The LAN port LEDs are lit for any local ports that are connected.
b. The WAN port LED is lit.
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If a port’s LED is lit, a link has been established to the connected device. If a LAN port is connected to a 100 Mbps device, verify that the port’s LED is green. If the port is 10 Mbps, the LED will be amber.
If any of these conditions does not occur, refer to the appropriate following section.

Power LED Not On

If the Power and other LEDs are off when your router is turned on:
Make sure that the power cord is properly connected to your router and that the power supply adapter is properly connected to a functioning power outlet.
Check that you are using the 7.5V DC power adapter supplied by NETGEAR for this product.
If the error persists, you have a hardware problem and should contact technical support.

LAN or WAN Port LEDs Not On

If either the LAN LEDs or WAN LED do not light when the Ethernet or USB connection is made, check the following:
Make sure that the Ethernet or USB cable connections are secure at the router and at the hub or workstation.
Make sure that power is turned on to the connected hub or workstation.
Be sure you are using the correct cable:
— When connecting the router’s WAN ADSL port, use the cable that was supplied with the
DG632.

Troubleshooting the Web Configuration Interface

If you are unable to access the router’s Web Configuration interface from a computer on your local network, check the following:
If you are using an Ethernet-connected computer, check the Ethernet connection between the computer and the router as described in the previous section.
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Make sure your computer’s IP address is on the same subnet as the router. If you are using the recommended addressing scheme, your computer’s address should be in the range of
192.168.0.2 to 192.168.0.254. Refer to “Verifying TCP/IP Properties” on page C-6 or
“Verifying TCP/IP Properties for Macintosh Computers” on page C-17 to find your
computer’s IP address. Follow the instructions in Appendix C to configure your computer.
Note: If your computer’s IP address is shown as 169.254.x.x:
Recent versions of Windows and MacOS will generate and assign an IP address if the computer cannot reach a DHCP server. These auto-generated addresses are in the range of
169.254.x.x. If your IP address is in this range, check the connection from the computer to the router and reboot your computer.
If your router’s IP address was changed and you do not know the current IP address, clear the router’s configuration to factory defaults. This will set the router’s IP address to 192.168.0.1. This procedure is explained in “Using the Reset button” on page 7-8.
Make sure your browser has Java, JavaScript, or ActiveX enabled. If you are using Internet Explorer, click Refresh to be sure the Java applet is loaded.
Try quitting the browser and launching it again.
Make sure you are using the correct login information. The factory default login name is admin and the password is password. Make sure that CAPS LOCK is off when entering this information.
If the router does not save changes you have made in the Web Configuration Interface, check the following:
When entering configuration settings, be sure to click the APPLY button before moving to another menu or tab, or your changes are lost.
Click the Refresh or Reload button in the Web browser. The changes may have occurred, but the Web browser may be caching the old configuration.

Troubleshooting the ISP Connection

If your router is unable to access the Internet, you should check the ADSL connection, then the WAN TCP/IP connection.

ADSL link

If your router is unable to access the Internet, you should first determine whether you have an ADSL link with the service provider. The state of this connection is indicated with the WAN LED.
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WAN LED Green or Blinking Green
If your WAN LED is green or blinking green, then you have a good ADSL connection. You can be confident that the service provider has connected your line correctly and that your wiring is correct.
WAN LED Blinking Yellow
If your WAN LED is blinking yellow, then your modem is attempting to make an ADSL connection with the service provider. The LED should turn green within several minutes.
If the WAN LED does not turn green, disconnect all telephones on the line. If this solves the problem, reconnect the telephones one at a time, being careful to use a microfilter on each telephone. If the microfilters are connected correctly, you should be able to connect all your telephones.
If disconnecting telephones does not result in a green WAN LED, there may be a problem with your wiring. If the telephone company has tested the ADSL signal at your Network Interface Device (NID), then you may have poor quality wiring in your house.
WAN LED Off
If the WAN LED is off, disconnect all telephones on the line. If this solves the problem, reconnect the telephones one at a time, being careful to use a microfilter on each telephone. If the microfilters are connected correctly, you should be able to connect all your telephones.
If disconnecting telephones does not result in a green WAN LED the problem may be one of the following:
Check that the telephone company has made the connection to your line and tested it.
Verify that you are connected to the correct telephone line. If you have more than one phone line, be sure that you are connected to the line with the ADSL service. It may be necessary to use a swapper if your ADSL signal is on pins 2 and 5 or the RJ-11 jack. The DG632 modem router uses pins 3 and 4.

Obtaining a WAN IP Address

If your modem is unable to access the internet, and your WAN LED is green or blinking green, you should determine whether the modem is able to obtain a WAN IP address from the ISP. Unless you have been assigned a static IP address, your modem must request an IP address from the ISP. You can determine whether the request was successful using the browser interface.
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To check the WAN IP address from the browser interface:
1. Launch your browser and select an external site such as www.netgear.com.
2. Access the Main Menu of the modem’s configuration at http://192.168.0.1.
3. Under the Maintenance heading check that an IP address is shown for the WAN Port.
If 0.0.0.0 is shown, your modem has not obtained an IP address from your ISP.
If your router is unable to obtain an IP address from the ISP, the problem may be one of the following:
Your ISP may require a Multiplexing Method or Virtual Path Identifier/Virtual Channel Identifier parameter. Verify with your ISP the Multiplexing Method and parameter value, and update the router’s ADSL Settings accordingly.
Your ISP may require a login program. Ask your ISP whether they require PPP over Ethernet (PPPoE) or PPP over ATM (PPPOA) login.
If you have selected a login program, you may have incorrectly set the Service Name, User Name and Password. See “Troubleshooting PPPoE or PPPoA”, below.
Your ISP may check for your computer's host name. Assign the computer Host Name of your ISP account to the modem in the browser-based Setup Wizard.
Your ISP only allows one Ethernet MAC address to connect to Internet, and may check for your computer’s MAC address. In this case:
Inform your ISP that you have bought a new network device, and ask them to use the router’s MAC address.

Troubleshooting PPPoE or PPPoA

The PPPoA or PPPoA connection can be debugged as follows:
1. Access the Main Menu of the router at http://192.168.0.1.
2. Under the Maintenance heading, select the Router Status link.
3. Click the Connection Status button.
4. If all of the steps indicate “OK” then your PPPoE or PPPoA connection is up and working.
5. If any of the steps indicates “Failed”, you can attempt to reconnect by clicking “Connect”. The
modem will continue to attempt to connect indefinitely.
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If you cannot connect after several minutes, you may be using an incorrect Service Name, User Name or Password. There also may be a provisioning problem with your ISP.
Note: Unless you connect manually, the modem will not authenticate using PPPoE or
PPPoA until data is transmitted to the network.

Troubleshooting Internet Browsing

If your modem can obtain an IP address but your computer is unable to load any Web pages from the Internet:
Your computer may not recognize any DNS server addresses.
A DNS server is a host on the Internet that translates Internet names (such as www addresses) to numeric IP addresses. Typically your ISP will provide the addresses of one or two DNS servers for your use. If you entered a DNS address during the modem’s configuration, reboot your computer and verify the DNS address as described in “Verifying TCP/IP Properties” on
page C-6. Alternatively, you can configure your computer manually with DNS addresses, as
explained in your operating system documentation.
Your computer may not have the modem configured as its TCP/IP modem.
If your computer obtains its information from the modem by DHCP, reboot the computer and verify the modem address as described in “Verifying TCP/IP Properties” on page C-6.

Troubleshooting a TCP/IP Network Using the Ping Utility

Most TCP/IP terminal devices and routers contain a ping utility that sends an echo request packet to the designated device. The device then responds with an echo reply. Troubleshooting a TCP/IP network is made very easy by using the ping utility in your computer.

Testing the LAN Path to Your Router

You can ping the router from your computer to verify that the LAN path to your router is set up correctly.
To ping the router from a PC running Windows 95 or later:
1. From the Windows toolbar, click the Start button and select Run.
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2.
In the field provided, type Ping followed by the IP address of the router, as in this example:
ping 192.168.0.1
3. Click OK.
You should see a message like this one:
Pinging <IP address> with 32 bytes of data
If the path is working, you see this message:
Reply from < IP address >: bytes=32 time=NN ms TTL=xxx
If the path is not working, you see this message:
Request timed out
If the path is not functioning correctly, you could have one of the following problems:
Wrong physical connections
— Make sure the LAN port LED is on. If the LED is off, follow the instructions in “LAN
or WAN Port LEDs Not On” on page 7-2.
— Check that the corresponding Link LEDs are on for your network interface card and
for the hub ports (if any) that are connected to your workstation and router.
Wrong network configuration
— Verify that the Ethernet card driver software and TCP/IP software are both installed
and configured on your PC or workstation.
— Verify that the IP address for your router and your workstation are correct and that the
addresses are on the same subnet.

Testing the Path from Your Computer to a Remote Device

After verifying that the LAN path works correctly, test the path from your PC to a remote device. From the Windows run menu, type:
PING -n 10 <IP address>
where <IP address> is the IP address of a remote device such as your ISP’s DNS server.
If the path is functioning correctly, replies as in the previous section are displayed. If you do not receive replies:
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— Check that your PC has the IP address of your router listed as the default modem. If the IP
configuration of your PC is assigned by DHCP, this information will not be visible in your PC’s Network Control Panel. Verify that the IP address of the router is listed as the default modem as described in “Verifying TCP/IP Properties” on page C-6.
— Check to see that the network address of your PC (the portion of the IP address specified
by the netmask) is different from the network address of the remote device.
— Check that your cable or DSL modem is connected and functioning.
— If your ISP assigned a host name to your PC, enter that host name as the Account Name in
the Basic Settings menu.
— Your ISP could be rejecting the Ethernet MAC addresses of all but one of your PCs. Many
broadband ISPs restrict access by only allowing traffic from the MAC address of your broadband modem, but some ISPs additionally restrict access to the MAC address of a single PC connected to that modem. If this is the case, you must configure your router to “clone” or “spoof” the MAC address from the authorized PC.

Restoring the Default Configuration and Password

This section explains how to restore the factory default configuration settings, changing the router’s administration password to password and the IP address to 192.168.0.1. You can erase the current configuration and restore factory defaults in two ways:
Use the Erase function of the Web Configuration Manager (see “Backing Up, Restoring, or
Erasing Your Settings” on page 5-1).
Use the Default Reset button on the rear panel of the router. Use this method for cases when the administration password or IP address is not known.

Using the Reset button

To restore the factory default configuration settings without knowing the administration password or IP address, you must use the Default Reset button on the rear panel of the router.
1. Press and hold the Default Reset button for at least 5 seconds. The USB LED will blink.
2. Release the Default Reset button and wait for the router to reboot.
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Appendix A
Technical Specifications
This appendix provides technical specifications for the DG632 ADSL Modem Router.
Network Protocol and Standards Compatibility
Data and Routing Protocols: TCP/IP, RIP-1, RIP-2, DHCP, PPP over Ethernet (PPPoE) or
PPP over ATM (PPPoA), RFC 1483 Bridged or Routed Ethernet, and RFC 1577 Classical IP over ATM
Power Adapter
North America: 120V, 60 Hz, input
United Kingdom, Australia: 240V, 50 Hz, input
Europe: 230V, 50 Hz, input
Japan: 100V, 50/60 Hz, input
All regions (output): 7.5VDC @ 1.0A output, 7.5W maximum
Physical Specifications
Dimensions: 6.9" x 4.7" x 1.1"
175 mm x 119 mm x 28 mm
Weight: 0.7 lbs.
0.3 kg
Environmental Specifications
Operating temperature: 0° to 40° C (32º to 104º F)
Operating humidity: 90% maximum relative humidity, noncondensing
Electromagnetic Emissions
Meets requirements of: FCC Part 15 Class B
EN 55 022 (CISPR 22), Class B
Interface Specifications
Technical Specifications A-1
Reference Manual for the Model DG632 ADSL Modem Router
LAN: 10BASE-T or 100BASE-Tx, RJ-45
USB 1.1
WAN: ADSL, RJ-11, pins 2 and 3
T1.413, G.DMT, G.Lite ITU Annex A or B
A-2 Technical Specifications
Appendix B
Network and Routing Basics
This chapter provides an overview of IP networks and routing.

Related Publications

As you read this document, you may be directed to various RFC documents for further information. An RFC is a Request For Comment (RFC) published by the Internet Engineering Task Force (IETF), an open organization that defines the architecture and operation of the Internet. The RFC documents outline and define the standard protocols and procedures for the Internet. The documents are listed on the World Wide Web at www.ietf.org and are mirrored and indexed at many other sites worldwide.

Basic Router Concepts

Large amounts of bandwidth can be provided easily and relatively inexpensively in a local area network (LAN). However, providing high bandwidth between a local network and the Internet can be very expensive. Because of this expense, Internet access is usually provided by a slower-speed wide-area network (WAN) link such as a cable or DSL modem. In order to make the best use of the slower WAN link, a mechanism must be in place for selecting and transmitting only the data traffic meant for the Internet. The function of selecting and forwarding this data is performed by a router.
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What is a Router?

A router is a device that forwards traffic between networks based on network layer information in the data and on routing tables maintained by the router. In these routing tables, a router builds up a logical picture of the overall network by gathering and exchanging information with other routers in the network. Using this information, the router chooses the best path for forwarding network traffic.
Routers vary in performance and scale, number of routing protocols supported, and types of physical WAN connection they support. The DG632 ADSL Modem Router is a small office router that routes the IP protocol over a single-user broadband connection.

Routing Information Protocol

One of the protocols used by a router to build and maintain a picture of the network is the Routing Information Protocol (RIP). Using RIP, routers periodically update one another and check for changes to add to the routing table.
The DG632 modem router supports both the older RIP-1 and the newer RIP-2 protocols. Among other improvements, RIP-2 supports subnet and multicast protocols. RIP is not required for most home applications.

IP Addresses and the Internet

Because TCP/IP networks are interconnected across the world, every machine on the Internet must have a unique address to make sure that transmitted data reaches the correct destination. Blocks of addresses are assigned to organizations by the Internet Assigned Numbers Authority (IANA). Individual users and small organizations may obtain their addresses either from the IANA or from an Internet service provider (ISP). You can contact IANA at www.iana.org.
The Internet Protocol (IP) uses a 32-bit address structure. The address is usually written in dot notation (also called dotted-decimal notation), in which each group of eight bits is written in decimal form, separated by decimal points.
For example, the following binary address:
11000011 00100010 00001100 00000111
is normally written as:
195.34.12.7
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C
N
C
C
The latter version is easier to remember and easier to enter into your computer.
In addition, the 32 bits of the address are subdivided into two parts. The first part of the address identifies the network, and the second part identifies the host node or station on the network. The dividing point may vary depending on the address range and the application.
There are five standard classes of IP addresses. These address classes have different ways of determining the network and host sections of the address, allowing for different numbers of hosts on a network. Each address type begins with a unique bit pattern, which is used by the TCP/IP software to identify the address class. After the address class has been determined, the software can correctly identify the host section of the address. The follow figure shows the three main address classes, including network and host sections of the address for each address type.
lass A
etwork Node
lass B
Network Node
lass C
Network Node
Figure 7-1: Three Main Address Classes
The five address classes are:
Class A Class A addresses can have up to 16,777,214 hosts on a single network. They use an eight-bit network number and a 24-bit node number. Class A addresses are in this range:
1.x.x.x to 126.x.x.x.
Class B Class B addresses can have up to 65,354 hosts on a network. A Class B address uses a 16-bit network number and a 16-bit node number. Class B addresses are in this range:
128.1.x.x to 191.254.x.x.
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Class C Class C addresses can have 254 hosts on a network. Class C addresses use 24 bits for the network address and eight bits for the node. They are in this range:
192.0.1.x to 223.255.254.x.
Class D Class D addresses are used for multicasts (messages sent to many hosts). Class D addresses are in this range:
224.0.0.0 to 239.255.255.255.
Class E Class E addresses are for experimental use.
This addressing structure allows IP addresses to uniquely identify each physical network and each node on each physical network.
For each unique value of the network portion of the address, the base address of the range (host address of all zeros) is known as the network address and is not usually assigned to a host. Also, the top address of the range (host address of all ones) is not assigned, but is used as the broadcast address for simultaneously sending a packet to all hosts with the same network address.

Netmask

In each of the address classes previously described, the size of the two parts (network address and host address) is implied by the class. This partitioning scheme can also be expressed by a netmask associated with the IP address. A netmask is a 32-bit quantity that, when logically combined (using an AND operator) with an IP address, yields the network address. For instance, the netmasks for Class A, B, and C addresses are 255.0.0.0, 255.255.0.0, and 255.255.255.0, respectively.
For example, the address 192.168.170.237 is a Class C IP address whose network portion is the upper 24 bits. When combined (using an AND operator) with the Class C netmask, as shown here, only the network portion of the address remains:
11000000 10101000 10101010 11101101 (192.168.170.237)
combined with:
11111111 11111111 11111111 00000000 (255.255.255.0)
Equals:
11000000 10101000 10101010 00000000 (192.168.170.0)
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C
As a shorter alternative to dotted-decimal notation, the netmask may also be expressed in terms of the number of ones from the left. This number is appended to the IP address, following a backward slash (/), as “/n.” In the example, the address could be written as 192.168.170.237/24, indicating that the netmask is 24 ones followed by 8 zeros.

Subnet Addressing

By looking at the addressing structures, you can see that even with a Class C address, there are a large number of hosts per network. Such a structure is an inefficient use of addresses if each end of a routed link requires a different network number. It is unlikely that the smaller office LANs would have that many devices. You can resolve this problem by using a technique known as subnet addressing.
Subnet addressing allows us to split one IP network address into smaller multiple physical networks known as subnetworks. Some of the node numbers are used as a subnet number instead. A Class B address gives us 16 bits of node numbers translating to 64,000 nodes. Most organizations do not use 64,000 nodes, so there are free bits that can be reassigned. Subnet addressing makes use of those bits that are free, as shown below.
lass B
Network Subnet Node
Figure 7-2: Example of Subnetting a Class B Address
A Class B address can be effectively translated into multiple Class C addresses. For example, the IP address of 172.16.0.0 is assigned, but node addresses are limited to 255 maximum, allowing eight extra bits to use as a subnet address. The IP address of 172.16.97.235 would be interpreted as IP network address 172.16, subnet number 97, and node number 235. In addition to extending the number of addresses available, subnet addressing provides other benefits. Subnet addressing allows a network manager to construct an address scheme for the network by using different subnets for other geographical locations in the network or for other departments in the organization.
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Although the preceding example uses the entire third octet for a subnet address, note that you are not restricted to octet boundaries in subnetting. To create more network numbers, you need only shift some bits from the host address to the network address. For instance, to partition a Class C network number (192.68.135.0) into two, you shift one bit from the host address to the network address. The new netmask (or subnet mask) is 255.255.255.128. The first subnet has network number 192.68.135.0 with hosts 192.68.135.1 to 129.68.135.126, and the second subnet has network number 192.68.135.128 with hosts 192.68.135.129 to 192.68.135.254.
Note: The number 192.68.135.127 is not assigned because it is the broadcast address
of the first subnet. The number 192.68.135.128 is not assigned because it is the network address of the second subnet.
The following table lists the additional subnet mask bits in dotted-decimal notation. To use the table, write down the original class netmask and replace the 0 value octets with the dotted-decimal value of the additional subnet bits. For example, to partition your Class C network with subnet mask 255.255.255.0 into 16 subnets (4 bits), the new subnet mask becomes 255.255.255.240.
Table 7-1. Netmask Notation Translation Table for One Octet
Number of Bits Dotted-Decimal Value
1 128
2 192
3 224
4 240
5 248
6 252
7 254
8 255
The following table displays several common netmask values in both the dotted-decimal and the masklength formats.
Table 7-2. Netmask Formats
Dotted-Decimal Masklength
255.0.0.0 /8
255.255.0.0 /16
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Table 7-2. Netmask Formats
255.255.255.0 /24
255.255.255.128 /25
255.255.255.192 /26
255.255.255.224 /27
255.255.255.240 /28
255.255.255.248 /29
255.255.255.252 /30
255.255.255.254 /31
255.255.255.255 /32
NETGEAR strongly recommends that you configure all hosts on a LAN segment to use the same netmask for the following reasons:
So that hosts recognize local IP broadcast packets
When a device broadcasts to its segment neighbors, it uses a destination address of the local network address with all ones for the host address. In order for this scheme to work, all devices on the segment must agree on which bits comprise the host address.
So that a local router or bridge recognizes which addresses are local and which are remote

Private IP Addresses

If your local network is isolated from the Internet (for example, when using NAT), you can assign any IP addresses to the hosts without problems. However, the IANA has reserved the following three blocks of IP addresses specifically for private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
NETGEAR recommends that you choose your private network number from this range. The DHCP server of the DG632 modem router is preconfigured to automatically assign private addresses.
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1
1
1
1
Regardless of your particular situation, do not create an arbitrary IP address; always follow the guidelines explained here. For more information about address assignment, refer to RFC 1597,
Address Allocation for Private Internets, and RFC 1466, Guidelines for Management of IP Address Space. The Internet Engineering Task Force (IETF) publishes RFCs on its Web site at
www.ietf.org.

Single IP Address Operation Using NAT

In the past, if multiple PCs on a LAN needed to access the Internet simultaneously, you had to obtain a range of IP addresses from the ISP. This type of Internet account is more costly than a single-address account typically used by a single user with a modem, rather than a router. The DG632 modem router employs an address-sharing method called Network Address Translation (NAT). This method allows several networked PCs to share an Internet account using only a single IP address, which may be statically or dynamically assigned by your ISP.
The router accomplishes this address sharing by translating the internal LAN IP addresses to a single address that is globally unique on the Internet. The internal LAN IP addresses can be either private addresses or registered addresses. For more information about IP address translation, refer to RFC 1631, The IP Network Address Translator (NAT).
The following figure illustrates a single IP address operation.
Private IP addresses assigned by user
IP addresses
92.168.0.2
92.168.0.3
92.168.0.4
92.168.0.5
192.168.0.1 172.21.15.105
Figure 7-3: Single IP Address Operation Using NAT
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Internet
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This scheme offers the additional benefit of firewall-like protection because the internal LAN addresses are not available to the Internet through the translated connection. All incoming inquiries are filtered out by the router. This filtering can prevent intruders from probing your system. However, using port forwarding, you can allow one PC (for example, a Web server) on your local network to be accessible to outside users.

MAC Addresses and Address Resolution Protocol

An IP address alone cannot be used to deliver data from one LAN device to another. To send data between LAN devices, you must convert the IP address of the destination device to its media access control (MAC) address. Each device on an Ethernet network has a unique MAC address, which is a 48-bit number assigned to each device by the manufacturer. The technique that associates the IP address with a MAC address is known as address resolution. Internet Protocol uses the Address Resolution Protocol (ARP) to resolve MAC addresses.
If a device sends data to another station on the network and the destination MAC address is not yet recorded, ARP is used. An ARP request is broadcast onto the network. All stations on the network receive and read the request. The destination IP address for the chosen station is included as part of the message so that only the station with this IP address responds to the ARP request. All other stations discard the request.

Related Documents

The station with the correct IP address responds with its own MAC address directly to the sending device. The receiving station provides the transmitting station with the required destination MAC address. The IP address data and MAC address data for each station are held in an ARP table. The next time data is sent, the address can be obtained from the address information in the table.
For more information about address assignment, refer to the IETF documents RFC 1597, Address Allocation for Private Internets, and RFC 1466, Guidelines for Management of IP Address Space.
For more information about IP address translation, refer to RFC 1631, The IP Network Address Translator (NAT).
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Domain Name Server

Many of the resources on the Internet can be addressed by simple descriptive names such as www.NETGEAR.com. This addressing is very helpful at the application level, but the descriptive name must be translated to an IP address in order for a user to actually contact the resource. Just as a telephone directory maps names to phone numbers, or as an ARP table maps IP addresses to MAC addresses, a domain name system (DNS) server maps descriptive names of network resources to IP addresses.
When a PC accesses a resource by its descriptive name, it first contacts a DNS server to obtain the IP address of the resource. The PC sends the desired message using the IP address. Many large organizations, such as ISPs, maintain their own DNS servers and allow their customers to use the servers to look up addresses.

IP Configuration by DHCP

When an IP-based local area network is installed, each PC must be configured with an IP address. If the PCs need to access the Internet, they should also be configured with a gateway address and one or more DNS server addresses. As an alternative to manual configuration, there is a method by which each PC on the network can automatically obtain this configuration information. A device on the network may act as a Dynamic Host Configuration Protocol (DHCP) server. The DHCP server stores a list or pool of IP addresses, along with other information (such as gateway and DNS addresses) that it may assign to the other devices on the network. The DG632 modem router has the capacity to act as a DHCP server.
The DG632 modem router also functions as a DHCP client when connecting to the ISP. The router can automatically obtain an IP address, subnet mask, DNS server addresses, and a gateway address if the ISP provides this information by DHCP.

Internet Security and Firewalls

When your LAN connects to the Internet through a router, an opportunity is created for outsiders to access or disrupt your network. A NAT router provides some protection because by the very nature of the Network Address Translation (NAT) process, the network behind the NAT router is shielded from access by outsiders on the Internet. However, there are methods by which a determined hacker can possibly obtain information about your network or at the least can disrupt your Internet access. A greater degree of protection is provided by a firewall router.
B-10 Network and Routing Basics
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