This article provides steps to troubleshoot when an ESXi is in disconnected or a not responding state in vCenter Server. In addition, it provides steps to help eliminate common causes by verifying the network configuration and management server agents are correct and confirm the availability of resources on per ESXi host.
Symptoms:
Unable to access the specified host, either it doesn't exist, the server software is not responding, or there is a network problem
VMware vSphere ESXi 6.x
VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x
VMware vCenter Server 6.x
VMware vCenter Server 7.x
VMware vCenter Server 8.x
For issues similar or related to ESXi hosts not responding, or other troubleshooting steps:
Virtual machines appear as invalid or orphaned in vCenter Server
ESXi host disconnects intermittently from vCenter Server
Troubleshooting the vCenter Server Agent when it does not start
Verifying the VMware vCenter Server Managed IP Address
TCP and UDP Ports required to access VMware vCenter Server, VMware ESXi and ESX hosts, and other network components
Determining why an ESXi/ESX host was powered off or restarted
ESXi/ESX host disconnects from vCenter Server after adding or connecting it to the inventory
Link state up or down for a vmnic interface on ESXi (broadcom.com)
Impact/Risks:
Refer to each section to understand the impact and risks for those relevant actions.