ZyXEL Communications NBG7815, Руководство пользователя

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Chapter 10 Wireless LAN
NBG7815 User’s Guide
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• Use the WPS screen to quickly set up a WiFi network with strong security without having to configure
security settings manually ( Section 10.5 on page 115 ).
• Use the Scheduling screen to set the times your WiFi is turned on and off ( Section 10.6 on page 117 ).
10.1.2 What You Should Know
Every WiFi network must follow these basic guidelines.
• Every WiFi client in the same WiFi network must use the same Service Set Identifier (SSID).
The SSID is the name of the WiFi network.
• If two WiFi networks overlap, they should use different channels.
Like radio stations or television channels, each WiFi network uses a specific channel, or frequency, to
send and receive information.
• Every WiFi client in the same WiFi network must use security compatible with the AP.
Security stops unauthorized devices from using the WiFi network. It also protects information that is
sent through the WiFi network.
WiFi Security Overview
The following sections introduce different types of WiFi security you can set up in the WiFi network.
SSID
Normally, the AP acts like a beacon and regularly broadcasts the SSID in the area. You can hide the
SSID instead, in which case the AP does not broadcast the SSID. In addition, you should change the
default SSID to something that is difficult to guess.
This type of security is fairly weak, however, because there are ways for unauthorized devices to get the
SSID. In addition, unauthorized devices can still see the information that is sent in the WiFi network.
MAC Address Filter
Every WiFi client has a unique identification number, called a MAC address.
1
A MAC address is usually
written using twelve hexadecimal characters
2
; for example, 00A0C5000002 or 00:A0:C5:00:00:02. To get
the MAC address for each WiFi client, see the appropriate User’s Guide or other documentation.
You can use the MAC address filter to tell the AP which WiFi clients are allowed or not allowed to use the
WiFi network. If a WiFi client is allowed to use the WiFi network, it still has to have the correct settings
(SSID, channel, and security). If a WiFi client is not allowed to use the WiFi 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 WiFi network. Furthermore, there
are ways for unauthorized devices to get the MAC address of an authorized WiFi client. Then, they can
use that MAC address to use the WiFi network.
1. Some WiFi devices, such as scanners, can detect WiFi networks but cannot use WiFi networks. These kinds of
WiFi devices might not have MAC addresses.
2. Hexadecimal characters are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.