3com WL-575 Manual De Usuario

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C

HAPTER

 5: S

YSTEM

 C

ONFIGURATION

The access point is configured by default as an “open system,” which broadcasts 
a beacon signal including the configured SSID. Wireless clients with an SSID 
setting of “any” can read the SSID from the beacon and automatically set their 
SSID to allow immediate connection to the nearest access point. 

To improve wireless network security, you have to implement two main functions:

„

Authentication: It must be verified that clients attempting to connect to the 
network are authorized users.

„

Traffic Encryption: Data passing between the access point and clients must be 
protected from interception and eavesdropping.

For a more secure network, the access point can implement one or a combination 
of the following security mechanisms:

„

Wired Equivalent Privacy (WEP)

„

IEEE 802.1x 

„

Wireless MAC address filtering 

„

Wi-Fi Protected Access (WPA or WPA2)

Both WEP and WPA security settings are configurable separately for each virtual 
access point (VAP) interface. MAC address filtering, and RADIUS server settings 
are global and apply to all VAP interfaces.

The security mechanisms that may be employed depend on the level of security 
required, the network and management resources available, and the software 
support provided on wireless clients.

A summary of wireless security considerations is listed in the following table.

Table 4   Wireless Security Considerations

WEP

Built-in support on all 802.11a 
and 802.11g devices

• Provides only weak security
• Requires manual key management

WEP over 802.1X

Requires 802.1X client support 
in system or by add-in software
(support provided in Windows 
2000 SP3 or later and Windows 
XP)

• Provides dynamic key rotation for improved WEP 

security

• Requires configured RADIUS server
• 802.1X EAP type may require management of 

digital certificates for clients and server

MAC Address 
Filtering

Uses the MAC address of client 
network card

• Provides only weak user authentication
• Management of authorized MAC addresses
• Can be combined with other methods for 

improved security

• Optionally configured RADIUS server