VCF 9.x: Supervisor Cluster Installation Fails with False Positive IP "overlaps with IP range" Error

Products

• VMware vSphere Kubernetes Service

Issue/Introduction

• When attempting to install or re-enable a Supervisor Cluster in VMware Cloud Foundation (VCF) 9.x on the management network, the task fails during validation with an error similar to:

  IP range (Address: <IP address>; Count: 5) overlaps with IP range (Address: <IP address>; Count: 5)

• The issue typically surfaces when enabling Supervisor Cluster after a previous Supervisor Cluster deployment failure and sSupervisor Cluster deployment was disabled.
• The error occurs even when using the same Management Network configuration and the same block of five consecutive static IP addresses.
• Disabling  of the Supervisor cluster completed successfully.
• The IP address flagged as "overlapped" (e.g., ##.##.##.231) is actually available and not assigned to any object in the environment
• If a different block of IPs is selected after a failure, the validation may still flag an IP that is not part of the new block (e.g., flagging .231 when the current range is .236 to .240).
  
  

Environment

VMware vSphere Kubernetes Service VCF 9.x

Cause

This is a false positive validation error caused by browser caching. The browser retains stale networking validation data from previous installation attempts, leading to incorrect overlap flags during subsequent retries.

Resolution

To resolve this issue and clear the false positive validation error:

1. Ensure the Supervisor Cluster is fully Disabled from the previous attempt.
2. Open a new browser instance or use an Incognito/Private window to access the VCF interface.
3. Clear the browser cache and cookies for the VCF management domain URL.
4. Re-enable the Supervisor Cluster using the intended Management Network configuration.

By using a clean browser session, the validation service will perform a fresh check of the IP availability without relying on cached data.