This video discusses and demonstrates enabling the vSphere Distributed Switch Health Check in vSphere 5.1 using the vSphere Web Client.
However, there are occasions when there are network connectivity issues in the user environment because these parameters are not configured properly. Network connectivity issues caused by configuration errors are often difficult to identify. This particularly is the case in an organization where the network administrators and vSphere administrators take management ownership of physical network switches and vSphere hosts respectively. In earlier versions of vSphere, there were no tools available that could help resolve such misconfigurations across the physical and virtual switches.
Source: http://kb.vmware.com/kb/2032878
Source: http://kb.vmware.com/kb/2032878