The vSphere Distributed Switch configuration on some hosts differed from that of VMware vCenter- "Out of Sync"

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

•  This banner alert in the Networking view is seen:

"The vSphere Distributed Switch configuration on some hosts differed from that of the vCenter Server."

• When viewing a list of hosts attached to the distributed switch, or from the manage hosts wizard under the vDS Status column, a yellow warning icon and the message below are seen:

"Out of sync"

• DVport reconfigure task may fail with the following error:
  
  "Cannot complete a vSphere Distributed switch operation for one or more host members"

Cause

There are a number of possible causes for this symptom. 

Resolution

Please refer to this KB for the appropriate scripted resolution steps:  KB 412915 - "The vSphere Distributed Switch configuration on some hosts differed from that of the vCenter Server" seen in the vCenter Networking icon view, Summary tab of a vDS