This article provides information on the VMware vSphere Distributed VMware vSphere Distributed Switch Health Check.

VMware vCenter Server 6.0.x
VMware vCenter Server 5.5.x
VMware vCenter Server 5.1.x

The health check support in VMware vSphere Distributed Switch 5.1 and later helps you identify and troubleshoot configuration errors in a vSphere Distributed Switch.

VMware vSphere runs regular health checks to examine certain settings on the distributed and physical switches to identify common errors in the networking configuration. The default interval between two health checks is 1 minute.

Configuration Error	Health Check	Required Configuration on the Distributed Switch
The VLAN trunk ranges configured on the distributed switch do not match the trunk ranges on the physical switch.	Checks whether the VLAN settings on the distributed switch match the trunk port configuration on the connected physical switch ports.	At least two active physical NICs
The MTU settings on the physical network adapters, distributed switch, and physical switch ports do not match.	Checks whether the physical access switch port MTU jumbo frame setting based on per VLAN matches the vSphere distributed switch MTU setting.	At least two active physical NICs
The teaming policy configured on the port groups does not match the policy on the physical switch port-channel	Checks whether the connected access ports of the physical switch that participate in an EtherChannel are paired with distributed ports whose teaming policy is IP hash	At least two active physical NICs and two hosts

Note: Health check is limited only to the access switch port to which the distributed switch uplink connects.

For more information, see:

• Enabling vSphere Distributed Switch health check in the vSphere Web Client (2032878)
  
• Enabling the vDS Health Check feature fails with inconsistent results (2079260)
  
• Network health check feature limitations in vSphere 5.1 and 5.5 (2034795)
  

Depending on the options that you select, vSphere Distributed Switch Health Check can generate a significant number of MAC addresses for testing teaming policy, MTU size, VLAN configuration, resulting in extra network traffic. For more information, see Network health check feature limitations in vSphere 5.1 and 5.5 (2034795).

After you disable vSphere Distributed Switch Health Check, the generated MAC addresses age out of your physical network environment according to your network policy.Enabling vSphere Distributed Switch health check in the vSphere Web Client
Network health check feature limitations in vSphere 5.1 and 5.5
Virtual Distributed Switch Health Check details pane displays invalid or incorrect information
Enabling the vDS Health Check feature fails with inconsistent results
VMware vSphere Distributed Switch の健全性チェック
VMware vSphere Distributed Switch 运行状况检查