20

Chapter 5: Configuring the Wireless-G Broadband Router

The Wireless Tab - Wireless Security

Wireless-G Broadband Router with SRX

WEP

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

(choose 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 the Passphrase or enter the WEP key manually.

Change these settings as described here and click the

Save Settings

button to apply your changes or

Cancel

Changes

to cancel your changes. For detailed instructions on configuring wireless security for the Router, turn to

“Appendix B: Wireless Security.”

Figure 5-19: Wireless Tab - Wireless Security

(WEP)

IMPORTANT:

If you are using WEP

encryption, always remember that each

device in your wireless network MUST use

the same WEP encryption method and

encryption key, or else your wireless network

21

Chapter 5: Configuring the Wireless-G Broadband Router

The Wireless Tab - Wireless MAC Filter

Wireless-G Broadband Router with SRX

The Wireless Tab - Wireless MAC Filter

Wireless access can be filtered by using the MAC addresses of the wireless devices transmitting within your

network’s radius.

Wireless MAC Filter

. To filter wireless users by MAC Address, either permitting or blocking access, click

Enable

.

If you do not wish to filter users by MAC Address, select

Disable

.

Prevent

. Clicking this button will block wireless access by MAC Address.

Permit Only

. Clicking this button will allow wireless access by MAC Address.

There are 50 fields provided in which you can list users, by MAC Address, whose access you wish to provide or

block. Just enter the MAC Address for the PC whose access you want to filter in one of the fields .For a more

convenient way to add MAC addresses, click the

Select

MAC Address From Networked Computers

button.

The

Networked Computers

screen will appear. Select the MAC Addresses you want. Then click the

Select

button.

Click the

Refresh

button if you want to refresh the screen. Click the

Close

button to return to the previous

screen.

Change these settings as described here and click the

Save Settings

button to apply your changes or

Cancel

Changes

to cancel your changes.

Figure 5-20: Wireless Tab - Wireless MAC Filter

Figure 5-21: Wireless Tab - Wireless MAC Filter - Networked

Computers

22

Chapter 5: Configuring the Wireless-G Broadband Router

The Wireless Tab - Advanced Wireless Settings

Wireless-G Broadband Router with SRX

The Wireless Tab - Advanced Wireless Settings

This tab is used to set up the Router’s advanced wireless functions. These settings should only be adjusted by an

expert administrator as incorrect settings can reduce wireless performance.

Basic Rate Set

. The Basic Rate setting is not actually one rate of transmission but a series of rates at which the

Router can transmit. The Router will advertise its Basic Rate to the other wireless devices in your network, so

they know which rates will be used. The Router will also advertise that it will automatically select the best rate

for transmission. The default setting is

Default

, when the Router can transmit at all standard wireless rates

(1-2Mbps, 5.5Mbps, 11Mbps, 18Mbps, and 24Mbps). Other options are

1-2Mbps

, for use with older wireless

technology, and

All

, when the Router can transmit at all wireless rates. The Basic Rate is not the actual rate of

data transmission. If you want to specify the Router’s rate of data transmission, configure the Transmission Rate

setting.

Transmission Rate

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

network. You can select from a range of transmission speeds, or you can select

Auto

to have the Router

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

negotiate the best possible connection speed between the Router and a wireless client. The default value is

Auto

.

CTS Protection Mode

. CTS (Clear-To-Send) Protection Mode should remain disabled unless you are having

severe problems with your Wireless-G products not being able to transmit to the Router in an environment with

heavy 802.11b traffic. This function boosts the Router’s ability to catch all Wireless-G transmissions but will

severely decrease performance.

Beacon Interval

. The default value is

100

. Enter a value between 1 and 65,535 milliseconds. The Beacon Interval

value indicates the frequency interval of the beacon. A beacon is a packet broadcast by the Router to synchronize

the wireless network.

DTIM Interval

. This value, between 1 and 255, 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 Router 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. The default value is

1

.

Fragmentation Threshold

. This value 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

reduction of the default value is recommended. In most cases, it should remain at its default value of

2346

.

Figure 5-22: Wireless Tab - Advanced Wireless Settings

fragmentation

: breaking a packet into smaller units

when transmitting over a network medium that

cannot support the original size of the packet.

cts

(clear to send): a signal sent by a wireless

device, signifying that it is ready to receive data

beacon interval

: data transmitted on your wireless

network that keeps the network synchronized

dtim

: a message included in data packets

that can increase wireless efficiency.

23

Chapter 5: Configuring the Wireless-G Broadband Router

The Security Tab - Firewall

Wireless-G Broadband Router with SRX

RTS Threshold

. Should you encounter inconsistent data flow, only minor reduction of the default value,

2347

, is

recommended. If a network packet is smaller than the preset RTS threshold size, the RTS/CTS mechanism will

not be enabled. The Router 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. The RTS Threshold value should remain at its default value

of

2347

.

Preamble Type

. The preamble defines the length of the CRC block for communication between the Router and

the roaming Network Card. (High network traffic areas should use the shorter preamble type.) Select the

appropriate preamble type,

Long Preamble (default)

or

Short Preamble

.

Network Density

. This setting is a reflection of the Router’s range. Setting the density to

Low

provides you with

a greater range. Setting the density to

High

gives you a lower range. The default setting is Medium.

Change these settings as described here and click the

Save Settings

button to apply your changes or

Cancel

Changes

to cancel your changes.

The Security Tab - Firewall

Firewall Protection

. Enable this feature to employ Stateful Packet Inspection (SPI) for more detailed review of

data packets entering your network environment.

Block WAN Ping

. Enable the Block WAN Ping feature by checking the box beside

Block WAN Ping

and you can

prevent your network from being “pinged,” or detected, by other Internet users. The Block WAN Ping feature also

reinforces your network security by hiding your network ports. Both functions of the Block WAN Ping feature

make it more difficult for outside users to work their way into your network. This feature is enabled by default.

VPN Passthrough

. These settings allow VPN tunnels using IPSec, PPTP, or L2TP protocols to pass through the

Router’s firewall. Internet Protocol Security (

IPSec

) is a suite of protocols used to implement secure exchange of

packets at the IP layer. To allow IPSec tunnels to pass through the Router, click

Enable

. Point-to-Point Tunneling

Protocol (

PPTP

) allows the Point-to-Point Protocol (PPP) to be tunneled through an IP network. To allow PPTP

tunnels to pass through the Router, click

Enable

. Layer 2 Tunneling Protocol (

L2TP

) is the method used to enable

Point-to-Point sessions via the Internet on the Layer 2 level. To allow L2TP tunnels to pass through the Router,

click

Enable

.

Change these settings as described here and click the

Save Settings

button to apply your changes or

Cancel

Changes

to cancel your changes.

Figure 5-23: Security Tab - Firewall

firewall

: a set of related programs located at a

network gateway server that protects the resources

of a network from users from other networks.

24

Chapter 5: Configuring the Wireless-G Broadband Router

The Access Restrictions Tab - Internet Access

Wireless-G Broadband Router with SRX

The Access Restrictions Tab - Internet Access

The

Internet Access

screen allows you to block or allow specific kinds of Internet usage and traffic, such as

Internet access, designated services, websites, and inbound traffic during specific days and times.

Internet Access Policy

. Access can be managed by a policy. Use the settings on this screen to establish an

access policy (after the

Save Settings

button is clicked). Selecting a policy from the drop-down menu will

display that policy’s settings. To delete a policy, select that policy’s number and click the

Delete

button. To view

all the policies, click the

Summary

button. (Policies can be deleted from the

Summary

screen by selecting the

policy or policies and clicking the

Delete

button. To return to the Internet Access tab, click the

Close

button.)

Status

. Policies are disabled by default. To enable a policy, select the policy number from the drop-down menu,

and click the radio button beside

Enable

.

You can create a policy to manage Internet access.

To create an Internet Access policy:

1.

Select a number from the

Internet Access Policy

drop-down menu.

2.

To enable this policy, click the radio button beside

Enable

.

3.

Enter a Policy Name in the field provided.

4.

Click the

Edit List

button to select which PCs will be affected by the policy. The

List of PCs

screen will appear.

You can select a PC by MAC Address or IP Address. You can also enter a range of IP Addresses if you want this

policy to affect a group of PCs. After making your changes, click the

Save Settings

button to apply your

changes or

Cancel Changes

to cancel your changes. Then click the

Close

button.

Figure 5-24: AAccess Restrictions Tab - Internet Access

Figure 5-25: Internet Policy Summary