Chapter 7 Wireless LAN

You can use the MAC address filter to tell the AP which wireless clients are allowed or not allowed to use the wireless network. If a wireless client is allowed to use the wireless network, it still has to have the correct settings (SSID, channel, and security). If a wireless client is not allowed to use the wireless network, it does not matter if it has the correct settings.

This type of security does not protect the information that is sent in the wireless network. Furthermore, there are ways for unauthorized devices to get the MAC address of an authorized wireless client. Then, they can use that MAC address to use the wireless network.

7.3.1.3 User Authentication

You can make every user log in to the wireless network before they can use it. This is called user authentication. However, every wireless client in the wireless network has to support IEEE 802.1x to do this.

For wireless networks, there are two typical places to store the user names and passwords for each user.

•In the AP: this feature is called a local user database or a local database.

•In a RADIUS server: this is a server used in businesses more than in homes.

If your AP does not provide a local user database and if you do not have a RADIUS server, you cannot set up user names and passwords for your users.

Unauthorized devices can still see the information that is sent in the wireless network, even if they cannot use the wireless network. Furthermore, there are ways for unauthorized wireless users to get a valid user name and password. Then, they can use that user name and password to use the wireless network.

Local user databases also have an additional limitation that is explained in the next section.

7.3.1.4 Encryption

Wireless networks can use encryption to protect the information that is sent in the wireless network. Encryption is like a secret code. If you do not know the secret code, you cannot understand the message.

The types of encryption you can choose depend on the type of user authentication. (See Section 7.3.1.3 on page 71 for information about this.)

Table 23 Types of Encryption for Each Type of Authentication

 

 

NO AUTHENTICATION

RADIUS SERVER

Weakest

No Security

WPA

 

 

 

 

 

 

Static WEP

 

 

 

 

 

 

 

WPA-PSK

 

 

 

 

 

 

 

 

Strongest

WPA2-PSK

WPA2

 

 

 

 

For example if the wireless network has a RADIUS server, you can choose WPA or WPA2. If users do not log in to the wireless network, you can choose no encryption, Static WEP, WPA-PSK, or WPA2-PSK.

Usually, you should set up the strongest encryption that every wireless client in the wireless network supports. For example, suppose the AP does not have a local user database, and you do

 

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NBG-417N User’s Guide