VMware ESXi host that is in a Disconnected state

VMware ESXi host that is in a Disconnected state

1. The affected ESXi host has been explicitly disconnected by a user from the vCenter Server. For more information, see the Disconnecting and Reconnecting a Host section of VMware vSphere 5.1 Documentation.
2. The ESXi host license has expired. For more information, see the Licensing for ESXi Hosts section of the VMware vSphere 6.0 Documentation.
3. Firewall issues that is preventing traffic to pass through Port 902. For more information, see TCP and UDP Ports required to access VMware vCenter Server, VMware ESXi and ESX hosts, and other network components (1012382)