Chapter 5 Wireless LAN
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.
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 User Authentication for information about this.)
Table 5 Types of Encryption for Each Type of Authentication
NO AUTHENTICATION RADIUS SERVER
Weakest | No Security | WPA | |
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| Static WEP |
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Stronges | WPA2 | ||
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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,
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 not have a RADIUS server. Therefore, there is no user authentication. Suppose the wireless network has two wireless clients. Device A only supports WEP, and device B supports WEP and WPA. Therefore, you should set up static WEP in the wireless network.
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