Uplink Network Profile Override Not Applying to Network Extension Appliance in HCX

Products

• VMware HCX

Issue/Introduction

When attempting to override an uplink network profile on an existing service mesh in VMware HCX, administrators may encounter a situation where the override does not properly apply to the Network Extension (NE) appliance while successfully applying to the Interconnect (IX) appliance. This inconsistent behavior can impact network traffic flow management and prevent administrators from implementing desired network configurations. While the HCX interface indicates a successful configuration change and the IX appliance adopts the new uplink profile as expected, the NE appliance continues to use its original uplink profile from the compute profile, creating a mismatch in the intended network configuration.

Environment

This behavior has been observed in environments with the following characteristics

• VMware HCX
• Configurations implementing network profile overrides at the service mesh level

Cause

The issue is related to how certain existing service meshes process and apply uplink profile override configurations. While the configuration change appears successful in the user interface, the system may not properly propagate all necessary changes to every component of the service mesh. This can result in incomplete application of the intended network configuration changes.

Resolution

To address this issue, administrators should first engage with Broadcom Support and then proceed with service mesh reconstruction if needed. Follow these steps:

1. Initial Support Engagement: Before attempting any service mesh changes, open a case with Broadcom Support. You will need to:
   • Collect and upload detailed logs including:
     • HCX logs from both source and target environments
     • ESXi host logs from affected systems
     • vCenter Server logs
   • Document and share the specific behavior you're observing
   • Work with support to confirm this is the known uplink profile override issue
   • Follow any additional troubleshooting steps provided by support
2. Service Mesh Reconstruction Process: Once support confirms the issue, proceed with rebuilding the service mesh:
   • Document all current service mesh settings and network extensions
   • Create a new service mesh with identical configurations
   • Plan for a maintenance window as network re-extension will be required
   • Remove the existing network extensions from the old service mesh
   • Extend the networks through the new service mesh
   • Verify all network extensions are functioning as expected
   • Remove the old service mesh after confirming successful migration
3. Post-Migration Verification:
   • Verify network connectivity for all extended networks
   • Test application accessibility and functionality
   • Confirm the new uplink profile is properly applied to both IX and NE appliances
   • Monitor network performance to ensure expected behavior

Important Notes

• The re-extension process will require a planned outage period
• Follow proper change management procedures throughout the process
• Maintain detailed documentation of existing configurations
• Perform thorough network connectivity testing after migration
• Consider upgrading to the latest version of HCX for optimal performance and functionality

By working with support first and then following these resolution steps methodically, administrators can ensure they're addressing the root cause correctly and implementing a proper solution. While creating a new service mesh requires more effort than a simple modification, it provides a clean implementation that correctly applies network profile overrides to all components of the service mesh.