NSX-T Segment creation fails with "Failed to find a vni pool" error

Products

• VMware NSX

Issue/Introduction

Symptoms:

• Overlay segment creation fails with the error "Failed to find a vni pool".
• When navigating to NSX-T UI > System > Fabric > Profiles > Configuration , one or both of the Default VNI pools, shows no value i.e. no VNI range.
• You some time in the past renamed the one or both of the Default VNI pool names.
• The Default VNI pool names are:
  • Default Vni Pool-1
  • Default Vni Pool-2
• Checking logs in /var/log/syslog.log, you can see similar messages : 

2022-xx-xx:33:01.805Z nsxt-mgr.vmw.com NSX 5528 SWITCHING [nsx@6876 comp="nsx-manager" errorCode="MP8301" level="ERROR" subcomp="manager"] LogicalSwitch segment_test create failed since vni pool cannot be found

Environment

VMware NSX-T Data Center
VMware NSX-T Data Center 3.x

Cause

Segment realization fails if the vni pool names are changed from the default value "Default Vni Pool-1" and "Default Vni Pool-2".

Resolution

This is resolved in NSX-T data center 3.2.1 available at VMware downloads.

Workaround:
If you have changed the default VNI pool names, lease revert the names to the original default vlaues:

• Default Vni Pool-1
• Default Vni Pool-2

If you have not changed the default VNI pool names or you are prevented from changing the name back to the default name(s) now, as you are on NSX-T 3.2.1 or greater, please contact Broadcom Support and refer to this KB article.