Linksys BEFSX41 - Instant Broadband EtherFast Cable/DSL Firewall... User manual

A Division of Cisco Systems, Inc.
®
Model No.
WIRED
with 4-Port Switch/VPN
Broadband Firewall Router
BEFSX41
User Guide
Endpoint

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Copyright and Trademarks
Linksys is a registered trademark or trademark of Cisco Systems, Inc. and/or its affiliates in the U.S. and certain
other countries. Copyright © 2004 Cisco Systems, Inc. All rights reserved.
How to Use this Guide
This User Guide has been designed to make understanding networking with the Router easier than ever. Look for
the following items when reading this Guide:
In addition to these symbols, there are definitions for technical terms that are presented like this:
Also, each figure (diagram, screenshot, or other image) is provided with a figure number and description, like
this:
Figure numbers and descriptions can also be found in the “List of Figures” section in the “Table of Contents”.
This exclamation point means there is a Caution or
Warning and is something that could damage your
property or the Router.
word: definition.
This checkmark means there is a Note of interest and
is something you should pay special attention to while
using the Router.
This question mark provides you with a reminder about
something you might need to do while using the Router.
Figure 0-1: Sample Figure Description
BEFSX41_V2-UG-40408ABW

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Table of Contents
Chapter 1: Introduction 1
Welcome 1
What’s in this Guide? 2
Chapter 2: Your Virtual Private Network (VPN) 4
Why do I need a VPN? 4
What is a Virtual Private Network? 5
Computer (using VPN client software that supports IPSec) to VPN Router 6
Chapter 3: Getting to Know the Router 7
The Back Panel 7
The Front Panel 8
Chapter 4: Connecting the Router 9
Overview 9
Connection Instructions 10
Chapter 5: Using The Router’s Web-based Utility 11
Overview 11
Navigating the Utility 11
Accessing the Utility 13
The Setup Tab 13
The Security Tab 25
The Restrict Access Tab 31
The Applications & Gaming Tab 33
Port Triggering 34
UPnP Forwarding 35
DMZ 37
The Administration Tab 38
The Status Tab 42
Appendix A: Troubleshooting 44
Common Problems and Solutions 44
Frequently Asked Questions 53
Appendix B: Upgrading Firmware 57
Appendix C: Finding the MAC Address and IP Address
for Your Ethernet Adapter 58

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Windows 98 or Me Instructions 58
Windows 2000 or XP Instructions 58
For the Router’s Web-based Utility 59
Appendix D: Windows Help 60
Appendix E: Maximizing VPN Security 61
Appendix F: Configuring IPSec between a Windows 2000 or
XP Computer and the Gateway 63
Introduction 63
Environment 63
How to Establish a Secure IPSec Tunnel 64
Appendix G: SNMP Functions 74
Appendix H: Glossary 75
Appendix I: Specifications 79
Appendix J: Warranty Information 80
Appendix K: Regulatory Information 81
Appendix L: Contact Information 82

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
List of Figures
Figure 2-1: VPN Router to VPN Router 6
Figure 2-2: Computer to VPN Router 6
Figure 3-1: Back Panel 7
Figure 3-2: Front Panel 8
Figure 4-1: Example of a Typical Network 9
Figure 4-2: Connect a PC 10
Figure 4-3: Connect the Internet 10
Figure 4-4: Connect the Power 10
Figure 5-1: The Router’s IP Address 13
Figure 5-2: Router Login 13
Figure 5-3: Setup Tab - Basic Setup 13
Figure 5-4: DHCP Connection Type 14
Figure 5-5: Static IP Connection Type 14
Figure 5-6: PPPoE Connection Type 15
Figure 5-7: RAS Connection Type 16
Figure 5-8: PPTP Connection Type 17
Figure 5-9: Heart Beat Signal Connection Type 18
Figure 5-10: L2TP Connection Type 19
Figure 5-11: Network Setup 20
Figure 5-12: Setup Tab - DynDNS.org 21
Figure 5-13: Setup Tab - TZO.com 21
Figure 5-14: Setup Tab - MAC Address Clone 22
Figure 5-15: Setup Tab - Advanced Routing 23
Figure 5-16: The Routing Table 24
Figure 5-17: Security Tab - Firewall 25
Figure 5-18: Security Tab - VPN 26
Figure 5-19: VPN Tunnel 27
Figure 5-20: Local and Remote Secure Group 27

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Figure 5-21: Remote Security Gateway 28
Figure 5-22: Key Management 28
Figure 5-23: Advanced VPN Tunnel Setup 29
Figure 5-24: Restrict Access Tab 31
Figure 5-25: Summary 31
Figure 5-26: List of PCs 32
Figure 5-27: Port Services 32
Figure 5-28: Applications & Gaming Tab - Port Range 33
Figure 5-29: Applications & Gaming Tab - Port Triggering 34
Figure 5-30: Applications & Gaming Tab - UPnP Forwarding 35
Figure 5-31: Applications & Gaming Tab - DMZ 37
Figure 5-32: Administration Tab - Management 38
Figure 5-33: Administration Tab - Log 39
Figure 5-34: View Log 39
Figure 5-35: Administration Tab - Diagnostics 40
Figure 5-36: Administration Tab - Factory Defaults 41
Figure 5-37: Administration Tab - Firmware Upgrade 41
Figure 5-38: Status Tab - Router 42
Figure 5-39: Status Tab - Local Network 43
Figure 5-40: DHCP Active IP Table 43
Figure B-1: Upgrade Firmware 57
Figure C-1: IP Configuration Screen 58
Figure C-2: MAC Address/Adapter Address 58
Figure C-3: MAC Address/Physical Address 59
Figure C-4: MAC Address Filter 59
Figure C-5: MAC Address Clone 59
Figure F-1: Local Security Screen 64
Figure F-2: Rules Tab 64
Figure F-3: IP Filter List Tab 64
Figure F-4: IP Filter LIst 65

Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Figure F-5: Filters Properties 65
Figure F-6: New Rule Properties 65
Figure F-7: IP Filter List 66
Figure F-8: Filters Properties 66
Figure F-9: New Rule Properties 66
Figure F-10: IP Filter List Tab 67
Figure F-11: Filter Acton Tab 67
Figure F-12: Security Methods Tab 67
Figure F-13: Authentication Methods 68
Figure F-14: Preshared Key 68
Figure F-15: New Preshared Key 68
Figure F-16: Tunnel Setting Tab 69
Figure F-17: Connection Type Tab 69
Figure F-18: Properties Screen 69
Figure F-19: IP Filter List Tab 70
Figure F-20: Filter Action Tab 70
Figure F-21: Authentication Methods Tab 70
Figure F-22: Preshared Key 71
Figure F-23: New Preshared Key 71
Figure F-24: Tunnel Setting Tab 71
Figure F-25: Connection Type 72
Figure F-26: Rules 72
Figure F-27: Local Computer 72
Figure F-28: VPN Tab 73

1
Chapter 1: Introduction
Welcome
Broadband Firewall Router with 4-Port Switch/VPN Endpoint
Chapter 1: Introduction
Welcome
Thank you for choosing the Broadband Firewall Router with 4-Port Switch/VPN Endpoint. This Router provides
your network with a high-security way to share a high-speed Internet connection as well as resources, including
files and printers.
How is this done? Inside this Router you have the Internet-access sharing ability of a standard Linksys Router,
along with the network expandibility of a 4-Port 10/100 Switch, and the network security functions of VPN.
But what does all of this mean?
At the core of this Router, is a standard, Linksys Router, providing you the ability to share your broadband,
Internet access within your network. This also comes with the protection of a firewall and the easy setup and
configuration you’ve come to expect from a Linksys Router. Add to that the network expandibility of a 4-port
10/100 Switch. The four ports in the back of the Router are all auto-detecting, meaning that the Router can tell if
you’re connecting a straight-through or cross-over cable, making this easier to use than ever. Finally, adding VPN
network security to the Router allows you to secure data, not just behind the Router, but as it is transmitted over
the Internet. VPNs, or Virtual Private Networks, create virtual tunnels that connect your PC to another across the
Internet, keeping the data secure as it passes from one to another.
In this User Guide, you’ll find all you need to setup, configure, and use the Router, including appendices
describing VPNs. Welcome to secure broadband networking.
broadband: an always-on, fast Internet connection
firewall: a set of related programs located at a
network gateway server that protects the resources
of a network from users from other networks
network: a series of computers or devices
connected for the purpose of data sharing,
storage, and/or transmission between users
switch: a data switch that connects computing
devices to host computers, allowing a large number
of devices to share a limited number of ports

2
Chapter 1: Introduction
What’s in this Guide?
Broadband Firewall Router with 4-Port Switch/VPN Endpoint
What’s in this Guide?
This user guide covers everything you’ll need to know about the Router. In addition to giving directions in the
Chapters about how to set it up and use it, several Appendices are provided for further information.
• Chapter 1: Introduction
This chapter describes the Router’s applications and this User Guide.
• Chapter 2: Networking Basics
This chapter briefly explains how a network functions.
• Chapter 3: Getting to Know the Router
This chapter provides a quick guide to the Router’s LED display on the front and ports on the back.
• Chapter 4: Connecting the Router
This chapter instructs you on how to connect the DSL modem to the Router and connect the PC(s) to the
Router.
• Chapter 5: Using the Router’s Web-based Utility
This chapter describes the Web-based Utility and the features available, so you can use and alter advanced
configuration settings.
• Appendix A: Troubleshooting
This appendix describes some possible problems and solutions, as well as frequently asked questions,
regarding installation and use of the Router.
• Appendix B: Upgrading Firmware
This appendix explains how you can upgrade the Router’s firmware.
• Appendix C: Finding the MAC Address and IP Address for Your Ethernet Adapter
This appendix instructs you on how to find the MAC address or Ethernet address of your PC’s Ethernet
network adapter.
• Appendix D: Windows Help
This appendix describes how you can use Windows Help for instructions about networking, such as installing
the TCP/IP protocol.
• Appendix E: Maximizing VPN Security
This appendix tells you how to get the most out of the VPN Router, using VPN tunnels.
DSL: an always-on broadband connection over
traditional phone lines
Ethernet: an IEEE standard network protocol that
specifies how data is placed on and retrieved from
a common transmission medium
firmware: the programming code that runs a
networking device
ISP (Internet Service Provider): a company that
provides access to the Internet
MAC (Media Access Control) address: the unique
address that a manufacturer assigns to each
networking device

3
Chapter 1: Introduction
What’s in this Guide?
Broadband Firewall Router with 4-Port Switch/VPN Endpoint
• Appendix F: Configuring IPSec between a Windows 2000 or XP PC and the VPN Router
So, how do you set your PCs up for VPN tunnels? This appendix tells you how.
• Appendix G: SNMP Functions
This appendix tells you about the Simple Network Management Protocol.
• Appendix H: Glossary
This appendix gives a brief glossary of terms frequently used in networking.
• Appendix I: Specifications
This appendix provides the technical specifications for the Router.
• Appendix J: Warranty Information
This appendix supplies the warranty information for the Router.
• Appendix K: Regulatory Information
This appendix supplies the regulatory information regarding the Router.
• Appendix L: Contact Information
This appendix provides contact information for a variety of Linksys resources, including Technical Support.
IPSec (Internet Protocol Security): A VPN protocol used to
implement secure exchange of packets at the IP layer
SNMP (Simple Network Management Protocol): a widely
used network monitoring and control protocol