ZyXEL Communications NWD-211AN -, Руководство пользователя

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Chapter 3 Wireless LANs
NWD271N User’s Guide
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• Open mode is implemented for ease-of-use and when security is not an issue. The
wireless station and the AP or peer computer do not share a secret key. Thus the wireless
stations can associate with any AP or peer computer and listen to any transmitted data that
is not encrypted.
• Shared mode involves a shared secret key to authenticate the wireless station to the AP or
peer computer. This requires you to enable the wireless LAN security and use same
settings on both the wireless station and the AP or peer computer.
• Auto authentication mode allows the NWD271N to switch between the open system and
shared key modes automatically. Use the auto mode if you do not know the authentication
mode of the other wireless stations.
3.3.1.2 IEEE 802.1x
The IEEE 802.1x standard outlines enhanced security methods for both the authentication of
wireless stations and encryption key management. Authentication can be done using an
external RADIUS server.
3.3.1.2.1 EAP Authentication
EAP (Extensible Authentication Protocol) is an authentication protocol that runs on top of the
IEEE 802.1x transport mechanism in order to support multiple types of user authentication. By
using EAP to interact with an EAP-compatible RADIUS server, an access point helps a
wireless station and a RADIUS server perform authentication.
The type of authentication you use depends on the RADIUS server and an intermediary AP(s)
that supports IEEE 802.1x. The NWD271N supports EAP-TLS, EAP-TTLS (at the time of
writing, TTLS is not available in Windows Vista) and EAP-PEAP. Refer to
Appendix B on
page 99 for descriptions.
For EAP-TLS authentication type, you must first have a wired connection to the network and
obtain the certificate(s) from a certificate authority (CA). Certificates (also called digital IDs)
can be used to authenticate users and a CA issues certificates and guarantees the identity of
each certificate owner.
3.3.1.3 WPA and WPA2
Wi-Fi Protected Access (WPA) is a subset of the IEEE 802.11i standard. WPA2 (IEEE
802.11i) is a wireless security standard that defines stronger encryption, authentication and
key management than WPA.
Key differences between WPA(2) and WEP are improved data encryption and user
authentication.
Both WPA and WPA2 improve data encryption by using Temporal Key Integrity Protocol
(TKIP), Message Integrity Check (MIC) and IEEE 802.1x. WPA and WPA2 use Advanced
Encryption Standard (AES) in the Counter mode with Cipher block chaining Message
authentication code Protocol (CCMP) to offer stronger encryption than TKIP.
If both an AP and the wireless clients support WPA2 and you have an external RADIUS
server, use WPA2 for stronger data encryption. If you don't have an external RADIUS server,
you should use WPA2-PSK (WPA2-Pre-Shared Key) that only requires a single (identical)
password entered into each access point, wireless gateway and wireless client. As long as the
passwords match, a wireless client will be granted access to a WLAN.