Supervisor VM upgrade failing with error "Unable to connect to Bootstrap API server"

Products

• VMware vSphere ESX 8.x
• VMware vSphere Kubernetes Service

Issue/Introduction

• The Supervisor VM upgrade is failing with error "Unable to connect to Bootstrap API server", while the IP in the error message is for existing Supervisor VMs:
  
  
• The error indicates the new Supervisor VM created during the upgrade is unable to connect to existing Supervisor VM over port 443 via the management network.
• "curl -kv https://<Destination-Supervisor-VM>" shows Connection Refused.

 

Environment

VMware vSphere ESX

Cause

There is a network issue between the Supervisor Control Plane VMs which results in the upgrade failure.

Resolution

Troubleshoot the network with packet captures while initiating the packets from the Source Supervisor VM:
Packet capture on ESXi using the pktcap-uw tool