VMware ESXi Host Disconnected from vCenter: Troubleshooting Runbook

Start with the management path

Separate VM workload connectivity from ESXi management connectivity. Check whether the host can reach its default gateway from DCUI and whether vCenter can reach the ESXi management address.

Validate DNS and IP identity

Confirm forward and reverse resolution from vCenter and the ESXi host. A hostname resolving to multiple or incorrect IP addresses can prevent vCenter from communicating with the intended management interface.

Test required ports

Check TCP 443 and the vCenter/ESXi communication path, including port 902 where applicable. A ping result alone does not prove that vSphere management traffic works.

Check management agents

Review hostd and vpxa state and logs when the host is reachable but vCenter cannot synchronize it. Management services can become unresponsive because of network, storage or resource pressure.

Check MTU and physical networking

Verify the management VMkernel path end to end. Look for MTU mismatches, LACP issues, VLAN errors and physical switch problems.

Check storage and host pressure

Datastore latency, APD/PDL conditions, high CPU or memory pressure can affect host responsiveness. Review vmkernel, vobd and vpxa logs before restarting services.

Reconnect only after the dependency is fixed

Reconnect the host after DNS, networking and management-service checks are clean. If a vCenter task is hung, investigate the task before repeatedly attempting reconnect.

esxcli network ip interface ipv4 get
esxcli network ip connection list
esxcli system hostname get
/etc/init.d/hostd status
/etc/init.d/vpxa status
vmkping <vCenter-IP>