Problem with MAC Pinning and new VLAN

[simon.geary]

[Cross posting to Nexus 1000V and UCS forums]

Hi all, I have a working setup of UCS 1.4 (3i) and Nexus 1000V 1.4 and as per the best practice guide am using 'channel-group auto mode on mac-pinning' on the Nexus uplinks. I am having trouble when adding a new VLAN into this environment, and it is a reproducable problem across two different installations.

I go through the usual VLAN creating process on the Nexus, the upstream network and within UCS itself. I create the new vethernet port profile and set it as an access port in the new VLAN. However when I attach a VM (either existing or new) to this new vethernet port profile within vCentre the VM cannot communicate with anything. However, if I disable MAC pinning with 'no channel-group auto mode on mac-pinning', the VM instantly starts to talk to the outside world and the new VLAN is up and running. I can then turn MAC pinning back on again and everything continues to work.

So the question is, is this behaviour normal or is there a problem? Disabling MAC pinning does have a brief interruption to the uplink so is not a viable long-term solution for the customer when they want to add new VLANs. Is there a way to add new VLANs in this scenario without any network downtime, however brief?

Thanks

[Robert Burns]

Full active thread will be maintained here:

https://supportforums.cisco.com/message/3420129#3420129

Solution will be posted here once resolved.

Robert

[Robert Burns]

Closing the loop on this.  You're hitting bug CSCto00715.

Symptom:
New MAC address is not learn on vem in the l2 table even though the mac address 
table is not overflow yet.
vemcmd show l2-emergency-aging-stats | grep "Number of entries that could not be inserted:" 
will show extremely large number. 

Conditions:
Nexus1000v VEM running on SV1.4 release.There are two CPU cores on the host. 
This issue may happen at race condition.

Workaround:
Reboot the ESX/ESXi host.

This is fixed in 1.4a release.

Regards,

Robert