CHAPTER 5: SYSTEM CONFIGURATION
SECURITY
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) | page | |
| IEEE 802.1x | page |
Wireless MAC address filtering | page | |
|
| page |
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
Security | Client Support | Implementation Considerations |
Mechanism |
|
|
WEP | |
| and 802.11g devices |
WEP over 802.1X | Requires 802.1X client support |
| in system or by |
| (support provided in Windows |
| 2000 SP3 or later and Windows |
| XP) |
MAC Address | Uses the MAC address of client |
Filtering | network card |
•Provides only weak security
•Requires manual key management
•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
•Provides only weak user authentication
•Management of authorized MAC addresses
•Can be combined with other methods for improved security
•Optionally configured RADIUS server
