Hi tdubb123,
Here are a couple things you can try. Iterate through the list until successful.
1. Perform a vMotion of the VM to another host and see if the problem persists.
2. From Edit Settings on the VM, make note of the port group it's on, then set it to "Unused or Quarantined", click ok, Then set it back to the original port group again
3. From Home> Inventory> Networking, Select your 1000v vDS in the left pane, and in the right pane select the Ports tab and review the State Column. Scroll through and see if the VM in question is "blocked". If so, click "Start Monitoring Port State" at the top right. Often this will clear the issue. If not proceed to step 4.
4. Identify which host the VM is on, and open an ssh session to the host. Then perform the following command to see if the VM's port is blocked:
vemcmd show port | grep -i <vmname>
5. If you are seeing a port blocked in either step 3 or 4 above, then perform the following to confirm the health of the VEM to VSM communication:
vemcmd show card | grep 'Primary VSM MAC'
Using the MAC address returned from the above, run the following command to perform the health check:
vem-health check <mac from above>
Example:
6. If any errors are reported on the health check above, review as appropriate. If the problem persists, perform a 'tail -fv /var/log/vmkernel.log' while attempting to connect the NIC or power the VM on. Also consider tailing the vmware.log in the VM's directory.
7. If the problem persists, determine if the issue affects only this VM by powering on another VM that uses the same port group, even if you have to deploy one from template if needed. You may also consider powering off a less important VM on that same port group and see if you can then get network connectivity when powering on the 'bad' VM.
8. Ok, if you got this far with no success then here's where things get technical. Check out this technote from Cisco:
Nexus 1000V VM Registration Troubleshoot - Cisco
If after all that the issue still persists, consider opening a VMware case. Let us know how things are going either way.