Throughput lower than expected for HCX Service Mesh over Direct Connect - VMware HCX [VMC on AWS]

Products

• VMware HCX
• VMware Cloud on AWS

Issue/Introduction

In a VMware Cloud (VMC) on AWS environment, you may experience significantly lower throughput than expected (e.g., 4mbps on a 10Gb link) for HCX migrations or network extensions. This typically occurs when a successful Service Mesh deployment defaults to the public Internet path instead of utilizing the intended AWS Direct Connect (DX) link.

Symptoms:

• Migration or Network Extension throughput is significantly lower than the available Direct Connect bandwidth.
• Service Mesh deployment status is "Green" or "Successful," but traffic analysis shows data routing over the external network.

Environment

• VMware HCX
• VMware Cloud on AWS
• AWS Direct Connect (DX)

Cause

By default, the HCX Service Mesh utilizes the externalNetwork profile for Uplink traffic. If the directConnectNetwork1 profile is not explicitly assigned an IP pool or is not manually selected as the Uplink in the Compute Profile, HCX defaults to the Internet path, which is often subject to lower throughput and higher latency than the dedicated Direct Connect link.

Resolution

To resolve this issue and ensure HCX traffic utilizes the Direct Connect link, follow these steps:

1. Assign an IP pool to the Direct Connect network profile:
   • Log in to the VMC Console.
   • Navigate to Inventory > SDDC > HCX > Settings.
   • Ensure a valid IP pool is assigned to the directConnectNetwork1 network profile.
     
     
2. Update the HCX Compute Profile:
   • Log in to the HCX Manager UI (Port 443).
   • Navigate to Infrastructure > Interconnect > Compute Profile.
   • Edit the Compute Profile associated with the site pairing.
   • In the Network Profiles section, select directConnectNetwork1 as the Uplink network.
     
     
     
3. Resynchronize the Service Mesh:
   • Navigate to Infrastructure > Interconnect > Service Mesh.
   • Select the impacted Service Mesh and click Resync to apply the configuration changes to the Interconnect (IX) and Network Extension (NE) appliances.

For software updates or downloads, see Download Broadcom Products and Software (KB 142814).

 

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