VMware HCX Compatibility and Upgrade Requirements for VCF 9.1

Products

• VMware Cloud on AWS

Issue/Introduction

Support agents or customers planning an upgrade to VMware Cloud Foundation (VCF) 9.1 may encounter concerns or failures regarding VMware HCX interoperability, specifically:
Questions regarding the support of HCX 4.11.x with vCenter Server 9.1.

Connectivity or service failures (e.g., envoy-hgw crashes) after the vCenter 9.1 upgrade.

Compatibility questions for environments paired with VMware Cloud on AWS (VMC on AWS).

Environment

VMware HCX 4.x

VMware Cloud on AWS

Cause

Strict Certificate Validation: vCenter 9.1 introduces a new Envoy-based gateway with strict certificate handling.

Older HCX 4.x appliances (including 4.11.x) present metadata/certificates that are incompatible with this gateway, causing the vmware-envoy-hgw service to crash.

Version Branch Support: VCF 9.1 is designed to work with the HCX 9.x branch (distributed as VCF Operations HCX).

However, HCX 9.x is not currently supported for use with VMC on AWS SDDCs.

Resolution

Scenario A: VCF 9.1 On-Premises Upgrade

To maintain compatibility with the vCenter 9.1 Envoy gateway, you must upgrade HCX to the 9.x branch.

Proactive Upgrade: Upgrade HCX Manager and all Service Mesh appliances to version 9.1 or later before upgrading VCF/vCenter to version 9.1.
Validation: Verify the upgrade path from your current HCX 4.x version to 9.x via the Broadcom Interoperability Matrix.

Scenario B: Mixed Environment with VMC on AWS

If your environment utilizes HCX to pair with VMware Cloud on AWS, special considerations apply:

Do Not Upgrade to HCX 9.x: VMC on AWS does not support HCX 9.x. You must remain on the HCX 4.x branch (e.g., 4.11.x) for these pairings.
Compatibility Conflict: Because HCX 4.x is incompatible with vCenter 9.1, customers with VMC on AWS pairings should not upgrade their on-premises vCenter to version 9.1 until a supported configuration (either HCX 9.x support on VMC or an HCX 4.x patch for vCenter 9.1) is released.

Additional Information

vCenter 9.1 envoy-hgw service crashes with HCX 4.11
HCX 9.x Supportability on VMware Cloud on AWS
Upgrade Sequence for VCF 9.1