Windows 8 may not be able to connect to some Cisco routers

Koskee seuraavia: Windows 8 EnterpriseWindows 8 NWindows 8 Pro


Windows 8 clients may not be able to connect to existing wireless infrastructures using some Cisco routers, while Windows 7 and XP machines do.

Windows 8 may encounter a problem when trying to connect to the Cisco Unified Wireless Network.  If the client is using WPA or WPA2 key management with AES encryption, then the connection may fail.  With "debug client" in effect on the Wireless LAN Controller, a message similar to the following is seen:

*dot1xMsgTask: Jun 12 20:23:37.471: 00:11:22:33:44:55 Retransmit failure for
EAPOL-Key M1 to mobile 00:11:22:33:44:55, retransmit count 5, mscb deauth count 0

Windows 8 supports IEEE 802.11w (2009) natively in the OS. The Client implementation complies with IEEE 802.11w specification. All Windows 8 certified WLAN miniport drivers are required to support IEEE 802.11w through Windows Hardware Certification program.  When Windows 8 clients attempt to connect to Cisco’s MFP capable APs, the connection fails. This failure is the result of an interoperability issue between Windows 8 IEEE 802.11w implementation and Cisco’s MFP implementation on their APs. The AP doesn’t report the correct “Key Descriptor version” for M1 in 4 way handshake. The client drops the unexpected M1 and thus the 4 way handshake fails.   Legacy clients that don’t support 802.11w do not have this issue.   
The issue is due to Cisco’s MFP implementation. The Cisco reference for this issue is CSCua29504. There are 2 known resolutions for this issue: 

1.    Update the Controller to updated Firmware Image: Cisco has fixed the issue in an update release. You can download the updated software from This option is highly recommended. This image has a fix for reporting correct “Key descriptor version” for M1 of 4 way handshake messages. 4 way handshakes complete successfully thus establishing a successful connection. This will resolve the connectivity issue described above and also allow you to use all Windows WLAN 8 features. 

2.     Roll Back to Pre-Windows 8 Drivers. Another option is to roll back to pre-Windows 8 drivers. These drivers can be obtained from the hardware manufacturer or their website. 

Note that this approach will disable all Windows 8 specific WLAN features and user experience will be equivalent to capabilities supported by pre-Windows 8 drivers.

More Information

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