ZyXEL Communications EMG6726-B10A, Руководство пользователя

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Chapter 7 Wireless
EMG6726/8726-B10A User’s Guide
93
The types of encryption you can choose depend on the type of authentication. (See Section 7.8.3.3 on
page 92 for information about this.)
For example, If users do not log in to the wireless network, you can choose no encryption or WPA2-PSK .
Usually, you should set up the strongest encryption that every device in the wireless network supports. For
example, suppose you have a wireless network with the EMG and you do not have a RADIUS server.
Therefore, there is no authentication.
Note: It is recommended that wireless networks use WPA2-PSK .
Many types of encryption use a key to protect the information in the wireless network. The longer the
key, the stronger the encryption. Every device in the wireless network must have the same key.
7.8.4 Signal Problems
Because wireless networks are radio networks, their signals are subject to limitations of distance,
interference and absorption.
Problems with distance occur when the two radios are too far apart. Problems with interference occur
when other radio waves interrupt the data signal. Interference may come from other radio
transmissions, such as military or air traffic control communications, or from machines that are
coincidental emitters such as electric motors or microwaves. Problems with absorption occur when
physical objects (such as thick walls) are between the two radios, muffling the signal.
7.8.5 BSS
A Basic Service Set (BSS) exists when all communications between wireless stations or between a wireless
station and a wired network client go through one access point (AP).
Intra-BSS traffic is traffic between wireless stations in the BSS. When Intra-BSS traffic blocking is disabled,
wireless station A and B can access the wired network and communicate with each other. When Intra-
BSS traffic blocking is enabled, wireless station A and B can still access the wired network but cannot
communicate with each other.
Table 23 Types of Encryption for Each Type of Authentication
NO AUTHENTICATION
Weakest No Security
Strongest WPA2-PSK