25

Chapter 5: Configuring the Wireless-G ADSL Home Gateway

The Wireless Tab

Wireless-G ADSL Home Gateway

WEP. WEP is a basic encryption method, which is not as secure as WPA. To use WEP, select a Default Key (this

indicates which Key to use) and a level of WEP encryption,

64 bits 10 hex digits

or

128 bits 26 hex digits

. Then

either generate a WEP key using a Passphrase or enter the WEP key manually.

•

WEP Encryption. An acronym for Wired Equivalent Privacy, WEP is an encryption method used to protect your

wireless data communications. WEP uses 64-bit or 128-bit keys to provide access control to your network

and encryption security for every data transmission. To decode data transmissions, all devices in a network

must use an identical WEP key. Higher encryption levels offer higher levels of security, but due to the

complexity of the encryption, they may decrease network performance. To enable WEP, select

64 bits 10 hex

digits

or

128 bits 26 hex digits

.

•

Default Transmit Key

Select which WEP key (1-4) will be used when the Gateway sends data. Make sure that

the receiving device (wireless computer or client) is using the same key.

•

Passphrase. Instead of manually entering WEP keys, you can enter a passphrase. This passphrase is used to

generate one or more WEP keys. It is case-sensitive and should not be longer than 32 alphanumeric

characters. (This Passphrase function is compatible with Linksys wireless products only and cannot be used

with Windows XP Zero Configuration. If you want to communicate with non-Linksys wireless products or

Windows XP Zero Configuration, make a note of the WEP key generated in the

Key 1

field, and enter it

manually in the wireless computer or client.) After you enter the Passphrase, click the

Generate

button to

create WEP keys.

•

WEP Keys 1-4. WEP keys enable you to create an encryption scheme for wireless network transmissions. If

you are not using a Passphrase, then manually enter a set of values. (Do not leave a key field blank, and do

not enter all zeroes; they are not valid key values.) If you are using 64-bit WEP encryption, the key must be

exactly 10 hexadecimal characters in length. If you are using 128-bit WEP encryption, the key must be exactly

26 hexadecimal characters in length. Valid hexadecimal characters are “0”-“9” and “A”-“F”.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes. For detailed instructions on configuring wireless security for

the Gateway, turn to “Appendix B: Wireless Security.”

Figure 5-16: WEP

26

Chapter 5: Configuring the Wireless-G ADSL Home Gateway

The Wireless Tab

Wireless-G ADSL Home Gateway

The Wireless Access Tab

Wireless Network Access

Wireless Network Access. Select

Allow All

you want all computers to have access to the wireless network. To

restrict access to the network, select

Restrict Access

, and then select

Prevent

to block access for the

designated computers or

Permit only

to permit access for the designated computers. Click the

Edit

MAC

Address Access List

button, and the

Mac Address Filter List

screen will appear.

Enter the MAC addresses of the computers you want to designate. To see a list of MAC addresses for wireless

computers or clients, click the

Wireless Client MAC List

button.

The

Wireless Client MAC List

screen will list computers, their IP addresses, and their MAC addresses. Click the

Refresh button to get the most up-to-date information. Click the

Enable MAC Filter

checkbox To add a specific

computer to the Mac Address Filter List, click the

Enable MAC Filter

checkbox and then the

Update Filter List

button. Click the

Close

button to return to the

Wireless Client MAC List

screen.

On the

Wireless Client MAC List

screen, click the

Save Settings

button to save this list, or click the

Cancel

Changes

button to remove your entries.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-17: Wireless Network Access

Figure 5-18: MAC Address Filter List

Figure 5-19: Wireless Client MAC List

27

Chapter 5: Configuring the Wireless-G ADSL Home Gateway

The Wireless Tab

Wireless-G ADSL Home Gateway

The Advanced Wireless Settings Tab

Advanced Wireless

On this screen you can access the advanced wireless features, including Authentication Type, Control TX Rate,

Beacon Interval, DTIM Interval, Fragmentation Threshold, and RTS Threshold.

•

Authentication Type. The default is set to

Auto

, which allows either Open System or Shared Key

authentication to be used. For Open System authentication, the sender and the recipient do not use a WEP

key for authentication but can use WEP for data encryption. To only allow Open System authentication, select

Open System

. For Shared Key authentication, the sender and recipient use a WEP key for both authentication

and data encryption. To only allow Shared Key authentication, select

Shared Key

. It is recommended that this

option be left in the default (Auto) mode, because some clients cannot be configured for Shared Key.

•

Control Tx Rates The default transmission rate is

Auto

. The rate should be set depending on the speed of your

wireless network. Select from a range of transmission speeds, or keep the default setting,

Auto

, to have the

Gateway automatically use the fastest possible data rate and enable the Auto-Fallback feature. Auto-Fallback

will negotiate the best possible connection speed between the Gateway and a wireless client.

•

Beacon Interval. The default value is

100

. The Beacon Interval value indicates the frequency interval of the

beacon. A beacon is a packet broadcast by the Gateway to synchronize the wireless network.

•

DTIM Interval. The default value is

1

. This value indicates the interval of the Delivery Traffic Indication

Message (DTIM). A DTIM field is a countdown field informing clients of the next window for listening to

broadcast and multicast messages. When the Gateway has buffered broadcast or multicast messages for

associated clients, it sends the next DTIM with a DTIM Interval value. Its clients hear the beacons and awaken

to receive the broadcast and multicast messages.

•

Fragmentation Threshold. This value should remain at its default setting of

2346

. It specifies the maximum

size for a packet before data is fragmented into multiple packets. If you experience a high packet error rate,

you may slightly increase the Fragmentation Threshold. Setting the Fragmentation Threshold too low may

result in poor network performance. Only minor modifications of this value are recommended.

•

RTS Threshold. This value should remain at its default setting of

2347

. If you encounter inconsistent data

flow, only minor modifications are recommended. If a network packet is smaller than the preset RTS

threshold size, the RTS/CTS mechanism will not be enabled. The Gateway sends Request to Send (RTS)

frames to a particular receiving station and negotiates the sending of a data frame. After receiving an RTS, the

wireless station responds with a Clear to Send (CTS) frame to acknowledge the right to begin transmission.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-20: Advanced Wireless Settings

28

Chapter 5: Configuring the Wireless-G ADSL Home Gateway

The Security Tab

Wireless-G ADSL Home Gateway

The Security Tab

This screen shows the VPN passthrough, firewall, and filter settings. Use these features to enhance the security

of your network.

VPN Passthrough

Virtual Private Networking (VPN) is a security measure that basically creates a secure connection between two

remote locations. Configure these settings so the Gateway will permit VPN tunnels to pass through.

•

IPSec Passthrough. Internet Protocol Security (IPSec) is a suite of protocols used to implement secure

exchange of packets at the IP layer. To allow IPSec Passthrough, click the

Enable

button. To disable IPSec

Passthrough, click the

Disable

button.

•

PPPoE Passthrough. PPPoE Passthrough allows your PC(s) to use the PPPoE client software provided by your

ISP. Some ISPs may request that you use this feature on the Gateway. To allow PPPoE Passthrough, click the

Enable

button. To disable PPPoE Passthrough, click the

Disable

button.

•

PPTP Passthrough. Point-to-Point Tunneling Protocol Passthrough is the method used to enable VPN sessions

to a Windows NT 4.0 or 2000 server. To allow PPTP Passthrough, click the

Enable

button. To disable PPTP

Passthrough, click the

Disable

button.

•

L2TP Passthrough. Layering 2 Tunneling Protocol Passthrough is an extension of the Point-to-Point Tunneling

Protocol (PPTP) used to enable the operation of a VPN over the Internet.To allow L2TP Passthrough, click the

Enable

button. To disable L2TP Passthrough, click the

Disable

button.

Firewall

You can enable or disable the firewall, select filters to block specific Internet data types, and block anonymous

Internet requests.

To use the firewall, click

Enable

. If you do not want to use the firewall, click

Disable

.

Additional Filters

•

Filter Proxy. Use of WAN proxy servers may compromise the Gateway's security. Denying Filter Proxy will

disable access to any WAN proxy servers. To enable proxy filtering, click the checkbox.

•

Filter Cookies. A cookie is data stored on your computer and used by Internet sites when you interact with

them. To enable cookie filtering, click the checkbox.

Figure 5-21: Security

29

Chapter 5: Configuring the Wireless-G ADSL Home Gateway

The Security Tab

Wireless-G ADSL Home Gateway

•

Filter Java Applets. Java is a programming language for websites. If you deny Java Applets, you run the risk

of not having access to Internet sites created using this programming language. To enable Java Applet

filtering, click the checkbox.

•

Filter ActiveX. ActiveX is a programming language for websites. If you deny ActiveX, you run the risk of not

having access to Internet sites created using this programming language. To enable ActiveX filtering, click the

checkbox.

Block WAN Requests

•

Block Anonymous Internet Requests. This keeps your network from being “pinged” or detected and

reinforces your network security by hiding your network ports, so it is more difficult for intruders to discover

your network. Select

Block Anonymous Internet Requests

to block anonymous Internet requests or de-

select it

to allow anonymous Internet requests.

If you want to see activity logs for your security measures, then click the

View Logs

button. Click the

Clear

button to clear the log information. Click the

pageRefresh

button to refresh the information. Click the

Previous

Page

button to go to the previous page of information. Click the

Next Page

button to move to the next page of

information.

When finished making your changes on this tab, click the

Save Settings

button to save these changes, or click

the

Cancel Changes

button to undo your changes.

Figure 5-22: Firewall Log