你是否用了NIC Teaming?
Microsoft Support Policy for NIC Teaming with Hyper-V
http://support.microsoft.com/kb/968703
Common symptoms exhibited due to improperly configured NIC Teaming software:
The following event is logged in the System event log on the Hyper-V server:
Log Name: System
Source: VMSMP
Event ID: 28
Level: Warning
Description: Port '97B1A2BA-D679-4290-AD9B-262DE33C16D6' was prevented from using MAC address '00-15-D5-04-F8-0C' because it is pinned to port 'BFA4D592-1F9D-8484-8ABF-9EDA1534529E'.
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若否，试一下人家的这个Solution？
VMSMP EventID 28
http://social.technet.microsoft.com/Forums/en-US/winserverhyperv/thread/0e2a51e7-12ad-4014-805d-28f0e6c0c823/
1. Deleted the virtual switch.
2. Stopped the three Hyper-v services.
3. Deleted remaining entries under the SwitchList Key and All NICs under the NicList Key of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\VMSMP\Parameters.
4. Restarted the services.
5. Recreated the virtual switch.
