vCenter Server Appliance Management Interface (VAMI) Unreachable Due to Missing Network Route

Products

• VMware vCenter Server

Issue/Introduction

A newly deployed vCenter Server Appliance (VCSA) has completed Stage 1 of its deployment, but the installer is unable to connect to the vCenter Server Management Interface (VAMI). This results in the following error:

"The installer is unable to connect to the vCenter Server Management Interface."

Consequently, the VAMI (e.g., https://<vCenter_FQDN>:5480 or <vCenter_IP_address>) is unreachable from external client machines. Attempts to ping the vCenter's IP address from external machines result in "Destination net unreachable." The vCenter VM is deployed and prompting for Stage 2 configuration, but Stage 2 cannot proceed due to the VAMI connectivity failure. Installer log files are typically located at paths like C:\Users\<username>\AppData\Local\Temp\11\vcsaUiInstaller.

Environment

VMware vCenter Server

Cause

The root cause of the inaccessibility is a missing network route for the vCenter Server's IP address (<vCenter_IP_address>) on an upstream network device (specifically identified as <router_or_L3_switch_IP_address>). This prevents network traffic from reaching the vCenter VM from external networks, even though the VM itself is operational and accessible from its local host.

• Evidence:
  • The vCenter installer failed with the message: "The installer is unable to connect to the vCenter Server Management Interface."
  • Ping to <vCenter_IP_address> from a client machine failed with "Destination net unreachable."
  • tracert performed for the vCenter IP indicated that traffic was halted at <router_or_L3_switch_IP_address>, suggesting a routing issue at that point.
  • Packet capture on the physical host's vmnic showed no incoming packets for <vCenter_IP_address>, confirming that the issue occurs before traffic reaches the host.
  • Successful ping from the host CLI to <vCenter_IP_address> confirms the vCenter VM's internal network configuration is likely correct and the VM is responsive, isolating the problem to the external network path.

Resolution

The issue requires investigation and remediation by the network infrastructure team. The proposed solution is to:

1. Identify the network device: Locate the network device with IP address <router_or_L3_switch_IP_address>.
2. Add missing route: Configure the appropriate static or dynamic route on this device to correctly forward traffic destined for <vCenter_IP_address> towards the vCenter Server's host.

• Justification: The tracert output definitively pointed to <router_or_L3_switch_IP_address> as the point of failure. Rectifying the routing configuration on this device will establish the necessary network path, allowing external machines and the installer to reach the vCenter VAMI, enabling the completion of Stage 2.