This issue occurs when a vDS is connected to multiple uplinks with different VLANs permitted, and the teaming/failover order is set on individual port groups to control which uplinks are used for that port group.
While this results in a working network configuration, Health Check does not distinguish between uplinks, and so reports any VLAN configured on the vDS as not supported for an uplink if it is not enabled on that particular network adapter. This affects the MTU, VLAN and Teaming & Failover test results.
The same alarm can also occur if a port group is configured with the VLAN type set to None. In this case, VLAN 0 shows as
not supported.
This can also occur because of the combination of the Health Check protocol design and Route Based on IP hash of Load Balancing algorithm. If Load balancing policy for the vDS switch port is configured as Route based on IP hash and EtherChannel is configured in the opposed physical switch, the physical switch may send the unicast frame to another uplink of host which the broadcast was not sent because of load balancing algorithm.
This situation can also arise from restoring a distributed switch configuration, where the uplinks created initially are included in the vDS restore referencing previously allocated VLAN Trunks, that may no longer be in use. If this is the case, the original vDS uplinks can be removed: