ESXi host not connecting back to cluster/datacenter after removing from the inventory.

Products

• VMware vSphere ESXi

Issue/Introduction

Unable to add ESXi host to the vCenter & it fails with the error : There was an error communicating with the remote host

SSH to the vCenter and traverse to /var/log/vmware/vmware-vpxd/vpxd.log and review the vpxd.log. The following error message may be seen:    
2025-05-22T10:08:41.753-06:00 info vpxd[7F1D96978700] [Originator@6876 sub=Default opID=AddHostWizard-add-45159-ngc:70005260-7a] [VpxLRO] -- ERROR task-2395 -- group-h4
 -- vim.Folder.addStandaloneHost: vmodl.fault.HostCommunication:
--> Result:
--> (vmodl.fault.HostCommunication) {
-->   faultCause = (vmodl.MethodFault) null,
-->   faultMessage = <unset>
-->   msg = ""
--> }
--> Args:
-->
--> Arg spec:
--> (vim.host.ConnectSpec) {
-->   hostName = "x.x.x.x",
-->   port = <unset>,
-->   sslThumbprint = <unset>,
-->   userName = "root",
-->   password = (not shown),
-->   vmFolder = 'vim.Folder:78a59c25-81c3-4169-85a6-61914d3e00c8:group-v3',
-->   force = true,
-->   vimAccountName = "vpxuser",
-->   vimAccountPassword = (not shown),
-->   managementIp = <unset>,

Environment

VMware vSphere 7.x

VMware vSphere 8.x

Cause

The ESXi Host vpxa password is already available in vCenter cache or the vCenter database.  THis results in the ESX Connect operation to fail with error message: "Error message: There was an error communicating with the remote host"

Resolution

1. SSH to ESX Host as root user and stop the vpxa service:    

  /etc/init.d/vpxa stop

2. On the vCenter WebClient UI, try re-adding the ESX Host.

Right click on the datacenter and select 'Add Host'

3. Walk through the wizard and provide ESXi host 'root' user credentials to connect.

4. ESXi integration/connect should work fine without issues.

On the ESX Host CLI session, verify the vpxa service came up automatically after the integration.

 /etc/init.d/vpxa status

The service status should show as running.

5. At this point, the ESX Host should start showing as connected again in the vCenter WebClient.