The disconnected ESXi Host failed to connect with an error "Authenticity of the host's SSL certificate is not verified" on vCenter Server

Products

• VMware vSphere ESXi

Issue/Introduction

• The ESXi host appears disconnected after the host certificate is updated. 

• When attempting to reconnect the host, the task fails and shows the error: "Authenticity of the host's SSL certificate is not verified".

Environment

VMware vSphere ESXi 8.x

Cause

For an unknown reason, the full certificate process does not complete.

Resolution

1. Connect to the host via SSH and then restart the management agents with the following commands:
   
   /etc/init.d/hostd restart
/etc/init.d/vpxa restart
/etc/init.d/rhttpproxy restart
   
   
2. Reconnect the ESXi host from vCenter Server.

Additional Information

If you want to check the validity of the host certificate in an SSH session, use this command:

openssl x509 -noout -in /etc/vmware/ssl/rui.crt