Enable witness traffic for the witness traffic VMkernel adapter on each ESXi host


  1. Log in to the vSphere Client.
  2. Click Menu > Hosts and Clusters.
  3. For each host in the stretched cluster, click Configure > Networking > VMkernel adapters to determine which VMkernel adapter to use for witness traffic. For example, vmk5.
  4. SSH to the first ESXi host in the stretched cluster.
  5. Log in as root and run the following command:
    esxcli vsan network ip add -i <vmkernel_adapter> -T=witness
    For example:
    esxcli vsan network ip add -i vmk5 -T=witness
  6. Verify that the VMkernel adapter is configured for witness traffic:
    esxcli vsan network list
  7. Verify that the ESXi host can access the witness host:
    vmkping -I <vmkernel_adapter> <witness_host_ip_address>
    Replace <vmkernel_adapter> with the VMkernel adapter configured for witness traffic, for example vmk5. Replace <witness_host_ip_address> with the witness host IP address.
  8. Repeat for each ESXi host in the stretched cluster.