Appendix B Wireless LANs

Dynamic WEP Key Exchange

The AP maps a unique key that is generated with the RADIUS server. This key expires when the wireless connection times out, disconnects or reauthentication times out. A new WEP key is generated each time reauthentication is performed.

If this feature is enabled, it is not necessary to configure a default encryption key in the Wireless screen. You may still configure and store keys here, but they will not be used while Dynamic WEP is enabled.

Note: EAP-MD5 cannot be used with Dynamic WEP Key Exchange

For added security, certificate-based authentications (EAP-TLS, EAP-TTLS and PEAP) use dynamic keys for data encryption. They are often deployed in corporate environments, but for public deployment, a simple user name and password pair is more practical. The following table is a comparison of the features of authentication types.

Table 100 Comparison of EAP Authentication Types

 

EAP-MD5

EAP-TLS

EAP-TTLS

PEAP

LEAP

Mutual Authentication

No

Yes

Yes

Yes

Yes

 

 

 

 

 

 

Certificate – Client

No

Yes

Optional

Optional

No

 

 

 

 

 

 

Certificate – Server

No

Yes

Yes

Yes

No

 

 

 

 

 

 

Dynamic Key Exchange

No

Yes

Yes

Yes

Yes

 

 

 

 

 

 

Credential Integrity

None

Strong

Strong

Strong

Moderate

 

 

 

 

 

 

Deployment Difficulty

Easy

Hard

Moderate

Moderate

Moderate

 

 

 

 

 

 

Client Identity

No

No

Yes

Yes

No

Protection

 

 

 

 

 

 

 

 

 

 

 

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 or WPA2 and WEP are improved data encryption and user authentication.

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.

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NWA-3500/NWA-3550 User’s Guide