vCenter Reports Interface is Blocked... but Interface is Up!

There appears to be a condition in the Nexus 1000v switch where vCenter will report interfaces on the DVS as Blocked, but verification from the VSM/VEM side show that they are in fact up and passing traffic.  This issue is tracked in Cisco defect ID: CSCub11514.

You can verify that the N1K interface is up in the forwarding state with the use of the 'vemcmd show port' output.  The workaround for this issue is to navigate to the Networking view of vCenter, select your N1K switch, click on the Ports tab, and then click on the blue 'Start Monitoring Port State'.  If you are hitting this issue, the interface will immediately switch to Link Up.  You can 'Stop Monitoring Port State' after the workaround has been performed.