Failed to expand a Stretched Cluster : Failed to validate hosts' network - Please make sure host management VLAN id and networkPoolId matches the specified fault domain,

Products

• VMware SDDC Manager

Issue/Introduction

• Unable to add additional ESXi Hosts in a AZ for a vSAN Strecthed Cluster.
  
  
• Description: Validate Expand Stretch Cluster ESXi Hosts(s) network 
  Progress messages : Failed to validate hosts' network - Please make sure host management VLAN id and networkPoolId matches the specified fault domain.
  
  

Environment

VCF 5.2

Cause

Renaming of the port groups was performed in vSphere.

Starting from VCF 5.2, Out of band changes are allowed to be made - "Out of Band Changes from vCenter: Out of Band changes from vCenter can be manually synced with SDDC Manager. This includes inventory changes (for example, adding a host to a cluster) and object name changes (for example, datacenter name, datastore name, port group name)."
https://docs.vmware.com/en/VMware-Cloud-Foundation/5.2/rn/vmware-cloud-foundation-52-release-notes/index.html#What's%20New 

This is supported on normal clusters but for a stretched cluster, we still need to follow the naming pattern of appending "az1_" and "az2_" for port groups in respective fault domains

 

Resolution

Rename the port groups back to prefix "az1_" for primary fault domain and  "az2_" for secondary fault domain.