Error: "The installer is unable to connect to the vCenter Appliance Management Interface" during the completion of Stage 1 of vCenter upgrade

Products

• VMware vCenter Server

Issue/Introduction

• During the completion of stage 1 of vCSA deployment, the installer returns the message "The installer is unable to connect to the vCenter Appliance Management interface"
• During the deployment of the Stage 1, the deployment target was chosen as ESXi host instead of vCenter server (managing the same ESXi host)
• On ESXi Host (where the target VCSA VM is deployed), the following may be seen:

ESXi - /var/run/log/vmkernel.log:

20xx-xx-xxTxx:xx:xx.xxxZ cpu85:41077519)NetPort: 1660: enabled port 0x2000077 with mac 00:50:56:a0:b2:72
20xx-xx-xxTxx:xx:xx.xxxZ cpu85:41077519)etherswitch: L2Sec_EnforcePortCompliance:172: client testvm01 requested mac address change to 00:50:56:a0:b2:72 on port 0x2000077, disallowed by vswitch policy
20xx-xx-xxTxx:xx:xx.xxxZ cpu85:41077519)etherswitch: L2Sec_EnforcePortCompliance:252: client testvm01 has policy violations on port 0x2000077. Port is blocked
20xx-xx-xxTxx:xx:xx.xxxZ cpu88:41077516)NetPort: 1879: disabled port 0x2000077
20xx-xx-xxTxx:xx:xx.xxxZ cpu52:65778)Net: 3740: disconnected client from port 0x2000077

Environment

VMware vCenter Server

Cause

During the upgrade, the installer deploys a vCenter appliance as target during stage 1. This step might involve a MAC change during the same stage which can cause the installer to report the error while enabling vCenter Server Appliance Management Interface (VAMI) access.

Resolution

This is an expected behavior.

As a workaround, perform one of the below steps:

• Option A: Deploy VCSA target appliance, set as the vCenter Server managing the ESXi Host instead of the ESXi host itself. 
  
  or
  
  
• Option B: Configure "reject mac address change" value to "Accept" on the vSwitch in case if host is selected as deployment target.

1. 1. Log in to the ESXi host UI that was chosen as deployment target
   2. Click networking on the left pane and click on virtual switches on the right
   3. Select the vSwitch on which the target portgroup is configured
   4. Click Edit Settings -> expand Security
   5. Change the value for "mac address change" to "accept" (reject if set as default in vSphere 7.x and later)
   6. Click ok

Additional Information

In some scenarios, same error message "The installer is unable to connect to the vCenter Appliance Management Interface." will be reported when port 5480 is blocked on firewall so windows workstation (from where upgrade is performed) is unable to connect to vCenter VAMI page (https://<vcenter ip/fqdn>:5480). Port 5480 needs to be unblocked between windows workstation and vCenter on firewall in order to proceed to upgrade stage two.