Cisco Linksys BEFVP41 v2 User manual

A Division of Cisco Systems, Inc.
®
Model No.
WIRED
with 4-Port 10/100 Switch
Cable/DSL VPN Router
BEFVP41 v2
User Guide
EtherFast
®

EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
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 © 2003 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
BEFVP41_V2-UG-31016NC KL

EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
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: Configuring the Router 11
Obtain an IP Automatically - DHCP 13
Static IP 13
PPPoE 14
RAS 14
PPTP 14
Heart Beat Signal 15
Chapter 6: Using The Router’s Web-based Utility 16
Overview 16
Navigating the Utility 16
Accessing the Utility 18
The Setup tab 18
The Security tab 28
The Access Restrictions tab 33
The Applications & Gaming tab 34
Port Triggering 35
UPnP Forwarding 36
DMZ 38
The Administration tab 39

EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
The Status tab 43
Appendix A: Troubleshooting 45
Common Problems and Solutions 45
Frequently Asked Questions 54
Appendix B: Upgrading Firmware 59
Appendix C: Finding the MAC Address and IP Address for Your Ethernet Adapter 60
Windows 98 or Me Instructions 60
Windows 2000 or XP Instructions 60
For the Router’s Web-based Utility 61
Appendix D: Windows Help 62
Appendix E: Maximizing VPN Security 63
Appendix F: Creating a VPN Tunnel between two VPN Routers 65
Appendix G: SNMP Functions 66
Appendix H: Glossary 67
Appendix I: Specifications 71
Appendix J: Warranty Information 73
Appendix K: Regulatory Information 74
Appendix L: Contact Information 77

EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
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: Router’s IP Address for Basic Setup 11
Figure 5-2: Router Login screen 11
Figure 5-3: Basic DHCP Setup 13
Figure 5-4: Basic Static IP Setup 13
Figure 5-5: Basic PPPoE Setup 14
Figure 5-6: The Registration URL 15
Figure 6-1: The Router’s IP Address 18
Figure 6-2: Router Login 18
Figure 6-3: Setup tab - Basic Setup 18
Figure 6-4: DHCP Connection type 19
Figure 6-5: Static IP Connection type 19
Figure 6-6: PPPoE Connection type 20
Figure 6-7: RAS Connection type 21
Figure 6-8: PPTP Connection type 22
Figure 6-9: Heart Beat Signal Connection type 23
Figure 6-10: Network Setup 24
Figure 6-11: Setup tab - DDNS 25
Figure 6-12: Setup tab - MAC Address Clone 25
Figure 6-13: Setup tab - Advanced Routing 26
Figure 6-14: The Routing Table 27

EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
Figure 6-15: Security tab -Firewall 28
Figure 6-16: Security tab - VPN 29
Figure 6-17: Local and Remote Secure Group 29
Figure 6-18: Remote Security Gateway 30
Figure 6-19: Key Management 30
Figure 6-20: Advanced VPN Tunnel Setup 32
Figure 6-21: Access Restrictions tab 33
Figure 6-22: Applications & Gaming tab - Port Range Forwarding 34
Figure 6-23: Applications & Gaming tab - Port Triggering 35
Figure 6-24: Applications & Gaming tab - UPnP Forwarding 36
Figure 6-25: Applications & Gaming tab - DMZ 38
Figure 6-26: Administration tab - Management 39
Figure 6-27: Administration tab - Log 40
Figure 6-28: Administration tab - Diagnostics 41
Figure 6-29: Administration tab - Factory Defaults 42
Figure 6-30: Administration tab - Firmware Upgrade 42
Figure 6-31: Status tab - Gateway 43
Figure 6-32: Status tab - Local Network 44
Figure 6-33: DHCP Active IP Table 44
Figure B-1: Upgrade Firmware 59
Figure C-1: IP Configuration Screen 60
Figure C-2: MAC Address/Adapter Address 60
Figure C-3: MAC Address/Physical Address 61
Figure C-4: MAC Address Filter 61
Figure C-5: MAC Address Clone 61
Figure F-1: The Web-based Utility’s VPN screen 65

1
Chapter 1: Introduction
Welcome
EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
Chapter 1: Introduction
Welcome
Thank you for choosing the EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch. 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?
EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
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, serveral 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: Configuring the Router
This chapter explains how to configure the Router using your web browser and the Router’s Web-based
Utility. You will configure the Router using the settings provided by your ISP.
• Chapter 6: 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.
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: theprogramming 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?
EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
• Appendix E: Maximizing VPN Security
This appendix tells you how to get the most out of the VPN Router, using VPN tunnels.
• 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

4
Chapter 2: Your Virtual Private Network (VPN)
Why do I need a VPN?
EtherFast Cable/DSL VPN Router with 4-Port 10/100 Switch
Chapter 2: Your Virtual Private Network (VPN)
Why do I need a VPN?
Computer networking provides a flexibility not available when using an archaic, paper-based system. With this
flexibility, however, comes an increased risk in security. This is why firewalls were first introduced. Firewalls
help to protect data inside of a local network. But what do you do once information is sent outside of your local
network, when emails are sent to their destination, or when you have to connect to your company's network
when you are out on the road? How is your data protected?
That is when a VPN can help. VPNs are called Virtual Private Networks because they secure data moving outside
of your network as if it were still within that network.
When data is sent out across the Internet from your computer, it is always open to attacks. You may already have
a firewall, which will help protect data moving around or held within your network from being corrupted or
intercepted by entities outside of your network, but once data moves outside of your network - when you send
data to someone via email or communicate with an individual over the Internet - the firewall will no longer protect
that data.
At this point, your data becomes open to hackers using a variety of methods to steal not only the data you are
transmitting but also your network login and security data. Some of the most common methods are as follows:
1) MAC Address Spoofing
Packets transmitted over a network, either your local network or the Internet, are preceded by a packet header.
These packet headers contain both the source and destination information for that packet to transmit efficiently.
A hacker can use this information to spoof (or fake) a MAC address allowed on the network. With this spoofed
MAC address, the hacker can also intercept information meant for another user.
2) Data Sniffing
Data "sniffing" is a method used by hackers to obtain network data as it travels through unsecured networks,
such as the Internet. Tools for just this kind of activity, such as protocol analyzers and network diagnostic tools,
are often built into operating systems and allow the data to be viewed in clear text.
3) Man in the middle attacks
Once the hacker has either sniffed or spoofed enough information, he can now perform a "man in the middle"
attack. This attack is performed, when data is being transmitted from one network to another, by rerouting the
packet: a unit of data sent over a network
vpn (Virtual Private Network): a security
measure to protect data as it leaves one
network and goes to another over the Internet