VCF Deployment Fails During Validation

Products

• VMware SDDC Manager / VCF Installer

Issue/Introduction

During the deployment of VMware Cloud Foundation (VCF) for multiple hosts and clusters, the deployment validation fails with an error indicating a Management VMkernel port configuration mismatch. 
Error Message: The management VMkernel port is connected to a DVS with MTU less than 1700. Remediation: To enable NSX Overlay using ESXi Management VMkernel Networking, please change the MTU configuration for the DVS in vCenter to a minimum MTU value of 1700 and retry.

Environment

VCF Installer 9.1

Cause

This issue occurs because the Distributed Virtual Switch (DVS) used for the Management VMkernel networking is configured with a default MTU value (typically 1500) that is lower than the required minimum of 1700. A minimum MTU of 1700 is necessary to support NSX Overlay traffic when using ESXi Management VMkernel Networking

Resolution

To resolve this issue, increase the MTU value on the Management DVS in vCenter to at least 1700.

1. Log in to the vSphere Client.
2. Navigate to Inventory > Networking.
3. Select the Distributed Switch (DVS) associated with the Management VMkernel networking.
4. Right-click the DVS and select Settings > Edit Settings.
5. Click Advanced.
6. Change the MTU value from the current setting (e.g., 1500) to a minimum of 1700 (or higher, such as 9000 if jumbo frames are supported in your environment).
7. Click OK to save the changes.
8. Retry the VCF deployment validation.

Additional Information

Understanding DVS MTU 1700 Configuration with NSX and HCX Deployments

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