In my vmware vSphere homelab, I found my Esxi hosts were showing disconnected in vCenter. I tried connecting esxi host through vmware vSphere web client. But I was getting error notification of reconnect host failure with the message Evaluation mode licenses expired.
Task Name: Reconnect host
Target: Esxi Host
Status: Cannot complete the license assignment operation "vCenter agen for VMware host" The Evaluation Mode license on "Host" Esxi Host can not be changed to. To downgrade the license, first disable the following features.
As I was using no licenses in my lab or didn't assigned any LICs to host, and when licenses are not in use, it works as Trial period and Evaluation mode is for 60 days. I wanted to assign new licenses and there is already a previous article written on this ADDING AND ASSIGNING VSPHERE LICENSES IN VCENTER SERVER AND ESXI. To assign newly assigned licenses to esxi host, Right click disconnected esxi host and select assign license. (DO NOT REMOVE HOST FROM VCENTER)
Next new Host - Assign License window will popup, select the licenses by choosing radio box, ADDING AND ASSIGNING VSPHERE LICENSES IN VCENTER SERVER AND ESXI and in the assignment validation check for issues, If no issues found click Ok.
Next follow the steps again, for reconnecting host by right clicking esxi host >> Connection >> Connect. Reconnect host message popup box open, Reconnecting a host will override any resource management changes that were made directly on the host while it was disconnected. Click Yes, next follow the step of adding host POWERCLI - CREATE DATACENTER AND ADD ESXI HOST IN VCENTER. It asks for root username and password.
Once all the requirement for connection is fulfilled you will see esxi host is connected successfully, with all the info.
Useful articles
PART 1 : BUILDING AND BUYING GUIDE IDEAS FOR VMWARE LAB
PART 2 : BUILDING AND HARDWARE BUYING GUIDE IDEAS FOR VMWARE LAB
PART 3 : MY VSPHERE LAB CONFIGURATION ON VMWARE WORKSTATION
PART 4 : CONFIGURING VMWARE WORKSTATION NETWORKING IN HOME LAB
