ESXi hosts transition to 'Not-Responding' state after vCenter services restart following a DNS entry change on ESXi hosts

Products

• VMware vSphere Kubernetes Service

Issue/Introduction

• After performing a restart of the vCenter Server services or rebooting the vCenter Server Appliance, ESXi hosts within a cluster transition to a "not-responding" state in the vSphere Client inventory.
  
  
• The DNS entries (A and PTR records) for these specific ESXi hosts had been recently modified on the DNS server, but the hosts' internal configurations were not updated to reflect this change.

Environment

• VMware vSphere ESXi

Cause

• The issue is caused by a mismatch between the ESXi host's internal hostname/domain configuration and the external DNS records. When vCenter Server restarts, it attempts to re-establish secure communication with all managed hosts. If the host's internal settings don't match the new FQDN resolved by vCenter, the vCenter-to-host handshake fails due to SSL certificate validation errors, forcing the host into a "not-responding" state.

Resolution

• The resolution requires updating the ESXi host's internal hostname and domain settings to ensure they align exactly with the current DNS records.
  
  
• Follow the procedure in the article below to change the hostname of the ESXi hosts.

Changing the hostname of an ESXi host