Linksys BEFSX41v1.44 Router Manual PDF (Setup & Configuration Guide)

Home

Manuals

Linksys

BEFSX41v1.44

Page 6 / 75 Scroll up to view Page 1 - 5

EtherFast

Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

Chapter 2: Your Virtual Private

Network (VPN)

Computer networking provides a flexibility not available when using an archa-

ic, 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 out-

side 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 with-

in 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 mov-

ing 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 individ-

ual 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.

Instant Broadband

Series

By default, a DHCP server (LAN side) is enabled on the Router.

If you already

have a DHCP server running on your network, you

must

disable one of the two

DHCP servers.

If you run more than one DHCP server on your network, you

will experience network errors, such as conflicting IP addresses.

To disable

DHCP on the Router, see the DHCP section in “Chapter 7: The Cable/DSL

Firewall Router’s Web-based Utility.”

This user guide covers the basic steps for setting up a network with a router.

After going through “Chapter 3: Getting to Know the EtherFast Cable/DSL

Firewall Router,” most users will only need to use the following chapters:

•

Chapter 4: Connect the Router

This chapter instructs you on how to connect the cable or DSL modem to

the Router and connect the PC(s) to the Router.

•

Chapter 5: Configure the PCs

This chapter instructs you on how to configure your PC(s) for a DHCP con-

nection, if the network settings are not already set to DHCP.

•

Chapter 6: Configure 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.

When you’re finished with the basic steps, then you are ready to connect to the

Internet. After the PC(s) can access the Internet through the Router, you can

alter the Router’s settings further; for example, you can adjust security features

and other settings to enable online gaming.

Note:

Even if you assign a static IP address to a PC, other PCs can

still use DHCP’s dynamic IP addressing, as long as the static IP

address is not within the DHCP range of the LAN IP Address.

If the dynamic IP addressing fails to provide a dynamic IP address, refer

to “Appendix A: Troubleshooting.”

Network Setup Overview

Why Do I Need a VPN?

Downloaded from

www.Manualslib.com

manuals search engine

Page 7 / 75

EtherFast

Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

There are two basic ways to create a VPN connection:

•

Firewall Router to Firewall Router

•

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

Router

The Firewall Router creates a “tunnel” or channel between two endpoints, so

that data transmissions between them are secure. A computer with VPN client

software that supports IPSec can be one of the two endpoints. Any computer

with the built-in IPSec Security Manager (Microsoft 2000 and XP ) allows the

Firewall Router to create a VPN tunnel using IPSec (refer to “Appendix C:

Configuring IPSec between a Microsoft Windows 2000 or XP PC and the

Firewall Router”). Other versions of Microsoft operating systems require addi-

tional, third-party VPN client software applications that support IPSec to be

installed.

Firewall Router to Firewall Router

An example of a Firewall Router-to-Firewall Router VPN would be as follows.

(See Figure 2-1.) At home, a telecommuter uses his Firewall Router for his

always-on Internet connection. His router is configured with his office's VPN

settings. When he connects to his office's router, the two routers create a VPN

tunnel, encrypting and decrypting data. As VPNs utilize the Internet, distance

is not a factor. Using the VPN, the telecommuter now has a secure connection

to the central office's network, as if he were physically connected.

Instant Broadband

Series

2) Data Sniffing

Data “sniffing” is a method used by hackers to obtain network data as it trav-

els through unsecured networks, such as the Internet. Tools for just this kind of

activity, such as protocol analyzers and network diagnostic tools, are often built

into operating systems and allow the data to be viewed in clear text.

3) Man in the middle attacks

Once the hacker has either sniffed or spoofed enough information, he can now

perform a “man in the middle” attack. This attack is performed, when data is

being transmitted from one network to another, by rerouting the data to a new

destination. Even though the data is not received by its intended recipient, it

appears that way to the person sending the data.

These are only a few of the methods hackers use and they are always develop-

ing more. Without the security of your VPN, your data is constantly open to

such attacks as it travels over the Internet. Data travelling over the Internet will

often pass through many different servers around the world before reaching its

final destination. That's a long way to go for unsecured data and this is when a

VPN serves its purpose.

A VPN, or Virtual Private Network, is a connection between two endpoints - a

VPN Router, for instance - in different networks that allows private data to be

sent securely over a shared or public network, such as the Internet. This estab-

lishes a private network that can send data securely between these two locations

or networks.

This is done by creating a “tunnel”. A VPN tunnel connects the two PCs or net-

works and allows data to be transmitted over the Internet as if it were still with-

in those networks. Not a literal tunnel, it is a connection secured by encrypting

the data sent between the two networks.

VPN was created as a cost-effective alternative to using a private, dedicated,

leased line for a private network. Using industry standard encryption and

authentication techniques—IPSec, short for IP Security—the VPN creates a

secure connection that, in effect, operates as if you were directly connected to

your local network. Virtual Private Networking can be used to create secure

networks linking a central office with branch offices, telecommuters, and/or

professionals on the road (travelers can connect to a VPN Router using any

computer with VPN client software that supports IPSec, such as SSH Sentinel).

What is a Virtual Private Network?

Figure 2-1

Downloaded from

www.Manualslib.com

manuals search engine

Page 8 / 75

EtherFast

Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

Chapter 3: Getting to Know the

EtherFast

Cable/DSL Firewall Router

The Router’s ports, shown in Figure 3-1, are where network cables are con-

nected

WAN

The

WAN

(Wide Area Network) port is where you connect

your cable or DSL modem through an Ethernet cable.

Your

modem connection will not work from any other port.

Ports 1-3

These three LAN (Local Area Network) ports are where you

will connect networked devices, such as PCs, print servers,

switches, and anything else you want to put on your network.

(These ports auto-detect crossover and straight-through

cables.)

Port 4/DMZ

operates like a regular LAN port to connect with

network devices, unless DMZ is enabled through the

Cable/DSL Firewall Router’s web-based utility. Once DMZ is

enabled, this port will be accessible with NO PROTECTION

from the firewall. Be sure to disable the DMZ function through

the web-based utility if you want this port shielded by the

Cable/DSL Firewall Router’s firewall. (This port auto-detects

crossover and straight-through cables.)

Power

The

Power

port is where you will connect the power adapter.

The Router’s Back Panel

Figure 3-1

Instant Broadband

Series

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

Router

The following is an example of a computer-to-Firewall Router VPN. (See

Figure 2-2.) In her hotel room, a traveling businesswoman dials up her ISP. Her

notebook computer has VPN client software that is configured with her office's

VPN settings. She accesses the VPN client software that supports IPSec and

connects to the Firewall Router at the central office. As VPNs utilize the

Internet, distance is not a factor. Using the VPN, the businesswoman now has

a secure connection to the central office's network, as if she were physically

connected.

For additional information and instructions about creating your own VPN,

please visit Linksys’s website at

www.linksys.com

or refer to “Appendix C:

Configuring IPSec between a Microsoft Windows 2000 or XP PC and the

Firewall Router.”

Important:

You must have at least one Firewall Router on one end of

the VPN tunnel. At the other end of the VPN tunnel, you must have a

second Firewall Router or a computer with VPN client software that

supports IPSec.

Figure 2-2

Downloaded from

www.Manualslib.com

manuals search engine

Page 9 / 75

EtherFast

Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

Instant Broadband

Series

WAN and LAN LEDs

Link/Act

Green

. The

Link/Act

LED serves two purposes. If the LED is con-

tinuously lit, the Router is successfully connected to a device

through the corresponding port (1, 2, 3 or 4/DMZ). If the LED is

flickering, the Router is actively sending or receiving data over

that port.

Full/Col

Green

. The

Full/Col

LED also serves two purposes. If this LED is

lit up continuously, the connection made through the correspon-

ding port is running in Full Duplex mode. If the LED flickers, the

connection is experiencing collisions. Infrequent collisions are

normal.

If this LED flickers too often, there may be a problem with your

connection. See “Appendix A: Troubleshooting” if you encounter

this problem.

100

Orange

. The

100

LED lights up when a successful 100Mbps con-

nection is made through the corresponding port.

If this LED does not light up, then your connection speed is 10

Mbps.

Proceed to “Chapter 4: Connect the Router.”

The Router’s LEDs, shown in Figure 3-2, provide a graphic display of activity.

Diag

Red

. The

Diag

LED lights up when the Router goes through its self-

diagnosis mode during every boot-up. It will turn off upon successful

completion of the diagnosis.

If this LED stays on for an abnormally long period of time, see

“Appendix A: Troubleshooting.”

DMZ

Green

. The DMZ LED lights up when the Cable/DSL Firewall

Router’s DMZ function is enabled. Enabling this function will remove

firewall protection from Port 4/DMZ.

Power

Green

. The

Power

LED lights up when the Router is powered on.

The Reset Button

Briefly pressing the Reset Button will refresh the Cable/DSL Firewall Router’s

connections, potentially clearing any jammed links.

Pressing the Reset Button and holding it in for a few seconds will clear all of

the Cable/DSL Firewall Router’s data. This should be done only if you are

experiencing heavy routing problems, and only after you have exhausted all of

the other troubleshooting options. By resetting the Cable/DSL Firewall Router,

you run the risk of creating conflicts between your PCs’ actual IP Addresses

and what the Cable/DSL Firewall Router thinks their IP Addresses should be.

You may be forced to reboot the entire system(s).

If the Cable/DSL Firewall Router locks up, simply power it down for three to

five seconds by removing the power cable from the Cable/DSL Firewall

Router’s Power Port. Leaving the power off for too long could result in the loss

of network connections.

The Router’s Front Panel LEDs

Figure 3-2

Downloaded from

www.Manualslib.com

manuals search engine

Page 10 / 75

EtherFast

Cable/DSL Firewall Router with 4-Port Switch/VPN Endpoint

Instant Broadband

Series

Repeat the above step to connect

more PCs or network devices to

the Router.

Connect the Ethernet cable from your cable or

DSL modem to the

WAN

port on the Router’s

back panel, as shown in Figure 4-3.

This is the

only port that will work for your modem con-

nection.

As shown in Figure 4-4, connect the power

adapter to the Power port on the back panel of

the Router, and then plug the power adapter

into a power outlet.

•

The

Power

LED on the front panel will light up green as soon as the power

adapter is connected properly. (The LEDs are shown in Figure 4-5.)

•

The

Diag

LED will light up red for a few

seconds when the Router goes through its

self-diagnostic test. This LED will turn

off when the self-test is complete.

Turn on the cable or DSL modem and PCs.

The Router’s hardware installation is now complete.

Figure 4-3

Figure 4-2

Figure 4-4

Figure 4-5

Chapter 4: Connect the Router

Unlike a hub or a switch, the Router’s setup consists of more than simply plug-

ging hardware together. You will have to configure your networked PCs to

accept the IP addresses that the Router assigns them (if applicable), and you

will also have to configure the Router with setting(s) provided by your Internet

Service Provider (ISP).

The installation technician from your ISP should have left the setup informa-

tion with you after installing your broadband connection. If not, you can call

your ISP to request the data.

Once you have the setup information you need for your specific type of Internet

connection, you can begin installation and setup of the Router.

The diagram in Figure 4-1 shows a typical configuration.

Before you begin, make sure that all of your hardware is powered off,

including the Router, PCs, hubs, switches, and cable or DSL modem.

Connect one end of an Ethernet cable to one of the LAN ports (labeled

, or

4/DMZ

) on the back of the Router, and the other end to a standard

port on a network device, e.g., a PC, print server, hub, or switch (see Figure

4-2).

Overview

Cable or DSL

Modem

Cable/DSL Firewall Router

PC with Ethernet Adapter

Notebook with Ethernet Adapter

WAN

LAN

Figure 4-1

Connecting Your Hardware Together and Booting Up

Downloaded from

www.Manualslib.com

manuals search engine

Rate

Popular Linksys Models

Famous Router IPs

Famous Router Companies

Bookmark Our Site

Share