ESXi Does Not Connect to vCenter and Does Not Load Administration From the Web

Products

• VMware vSphere ESXi

Issue/Introduction

ESXi is showing as "Not Responding" in the vSphere client and its administrative web GUI will also not load. 

Environment

VMware ESXi

Cause

The host is unable to send heartbeats to the vCenter over UDP port 902 to verify that it is operational/functioning. By default this is done every seconds with the host going into a "Not Responding" state if the vCenter does not receive a heartbeat packet within 60 seconds by default. The service responsible for this is the the Host's hostd service.

Resolution

Troubleshooting an ESXi host in a "not responding"/"disconnected" state