33
Security Mode
A wireless network uses radio, which is open to the public, as its data transmission medium. If the wireless
network is not protected by necessary measures, any client can connect to the network to use the resources of
the network or access unprotected data over the network. To ensure communication security, transmission links
of wireless networks must be encrypted for protection.
The AP supports various security modes for network encryption, including None, WEP, WPA-PSK, WPA2-PSK,
Mixed WPA/WPA2-PSK, WPA, and WPA2.
None
It indicates that any wireless client can connect to the wireless network. This option is not
recommended because it affects network security.
WEP
It uses a static key to encrypt all exchanged data, and ensures that a wireless LAN has the same level of
security as a wired LAN. Data encrypted based on WEP can be easily cracked. In addition, WEP
supports a maximum wireless network throughput of only 54 Mbps. Therefore, this security mode is
not recommended.
WPA-PSK, WPA2-PSK, and Mixed WPA/WPA2-PSK
Mixed WPA/WPA2-PSK indicates that wireless clients can connect to a wireless network using either
WPA-PSK or WPA2-PSK.
In these security modes, an AP adopts a preshared key for authentication, and generates another key
for data encryption. This prevents the vulnerability caused by static WEP keys, and makes the security
modes suitable for ensuring security of home wireless networks. Nevertheless, because the initial
preshared key for authentication is manually set and all clients use the same key to connect to the
same AP, the key may be disclosed unexpectedly. This makes the security modes not suitable for
scenarios where high security is required.
WPA and WPA2
To address the key management weakness of WPA-PSK and WPA2-PSK, the WiFi Alliance puts forward
WPA and WPA2, which use 802.1x to authenticate clients and generate data encryption–oriented root
keys. WPA and WPA2 use the root keys to replace the preshared keys that set manually, but adopt the
same encryption process as WPA-PSK and WPA2-PSK.
WPA and WPA2 uses 802.1x to authenticate clients and the login information of a client is managed by
the client. This effectively reduces the probability of information leakage. In addition, each time a client
connects to an AP that adopts the WPA or WPA2 security mode, the RADIUS server generates a data
encryption key and assigns it to the client. This makes it difficult for attackers to obtain the key. These
features of WPA and WPA2 help significantly increase network security, making WPA and WPA2 the
preferred security modes of wireless networks that require high security.
7.1.2 Changing the Basic Settings
To change the basic settings of an SSID, perform the following procedure:
Step 1 Choose Wireless > Basic.
Step 2 Select the SSID from the SSID drop-down list box.
Step 3 Change the parameters as required. Generally, you only need to change the Enable, SSID, and Security
Mode settings.
Step 4 Click Save.