Deployment prechecks for NSX-T show: "Edge node uplink IP and BGP peer IP are not in the same subnet."

Products

• VMware Cloud Foundation

Issue/Introduction

Symptoms:

Deployment prechecks for NSX-T cluster show: "Edge node uplink IP and BGP peer IP are not in the same subnet."

 

Workflow fails on: "Validate IP Address Assigned to Same Subnet."

Environment

VMware Cloud Foundation 4.x

Cause

Even though NSX-T is capable of functioning with the BGP neighbor on a different subnet by modifying the Max Hop Limit to 2 or higher; this configuration is not supported by VCF.

Resolution

Deploying a NSX-T cluster with this network configuration is not supported using VCF. This is a deliberate design decision stemming from VMware Validated Designs, and is intended to enhance security.

Workaround:

1. Deploy the NSX-T Edge cluster using VCF claiming an intent to use static routing rather than BGP.
2. After the deployment completes, change the cluster to BGP directly in the NSX Manager UI.

Additional Information

Bug 3217161 – [SR][23431589505][TBC Corporation][PLT] Edge node uplink IP and BGP peer IP are not in the same subnet (vmware.com)

Impact/Risks:

As the workaround requires a change made outside of SDDC Manager, the NSX-T Edge cluster will primarily need to be managed directly via the NSX-T UI, external to the SDDC Manager.