A single host in a four-node AHV-based cluster experiences a complete network failure.

In the case of a single host in a four-node AHV-based cluster experiencing a complete network failure, the user VMs running on that host will stay up, but will be unreachable until connectivity is restored. This is because if more than enough resources exist in the cluster to tolerate a node failure, the VMs will continue to run, but will be unable to communicate with other nodes in the cluster due to the network failure. This is stated in the official Nutanix Certified Associate (NCA) v6.5 study guide on page 49, under the heading “Virtual Machine Availability in the Event of Node Failure”.