Health Check allows vSphere to analyse the attributes of the Distributed Switch, and compare them to the attributes of the physical switch. It can be use to highlight misconfiguration such as invalid MTU sizes, VLANs, NIC Teaming and failover. For instance an alarm can be raised when the Distribute Switch refers to a VLAN on a portgroup, which isn’t available at the physical layer. By default Health Check is not enabled.
1. Select the Distributed Switch, and click the Manage Tab
2. In the Settings column, select Health check
3. The Edit button to enable the feature.
Viewing Health Check Status
1. Select the Distributed Switch, and click the Monitor tab
2. Select the Health Column
3. Problems will be flagged with a yellow exclamation mark on each affect host.
In this case flagging up that although VLAN101 is available, VLAN102 is not accessible to either vmnic2 or vmnic3 on the host. With further investigation it became clear that whilst VLAN101/103/104 had the vmnic2/3 of each host enabled for tagging – VLAN102 had not been enabled for VLAN Tagging. In error the FT Portgroup was not enabled for VLAN was attemtping to use VLAN0 which did not exist.
These issues were resolved to and the health check refreshed like so – with VLAN103 being used for the FT communication.
