The health check service helps identify and troubleshoot configuration errors in vSphere distributed switches.

Health check helps identify the following common configuration errors.

  • Mismatching VLAN trunks between an ESXi host and the physical switches it's connected to.

  • Mismatching MTU settings between physical network adapters, distributed switches, and physical switch ports.

  • Mismatching virtual switch teaming policies for the physical switch port-channel settings.

Health check monitors VLAN, MTU, and teaming policies.

VLANs

Checks whether the VLAN settings on the distributed switch match the trunk port configuration on the connected physical switch ports.

MTU

For each VLAN, determines whether the MTU size configuration for jumbo frames on the physical access switch port matches the distributed switch MTU setting.

Teaming policies

Determines whether the connected access ports of the physical switch that participate in an EtherChannel are paired with distributed ports whose teaming policy is Route based on IP hash.

Health check is limited to the access switch port to which the NICs of the ESXi hosts are connected.

Table 1. Design Decisions on Distributed Switch Health Check

Design ID

Design Decision

Design Justification

Design Implication

ROBO-VI-NET-002

Enable vSphere Distributed Switch Health Check on the virtual distributed switch.

vSphere Distributed Switch Health Check verifies that all VLANS are trunked to all ESXi hosts attached to the vSphere Distributed Switch and MTU sizes match the physical network.

You must have a minimum of two physical uplinks to use this feature.

A MAC address is assigned per VLAN per ESXi host. With many tenant workload VLANs and many hosts, switch MAC tables might overflow.

Note:

For VLAN and MTU checks, at least two physical NICs for the distributed switch are required. For a teaming policy check, at least two physical NICs and two hosts are required when applying the policy.