Error "subnets must be specified for connected segment" while disabling DHCP

Products

• VMware NSX

Issue/Introduction

Disabling DHCP fails with the error "BadRequestException: 400: Client Error for url: https://<IP address>:9696/v2.0/subnets/########-####-####-####-############, Invalid input for operation: For segment /infra/segments/########-####-####-####-############, subnets must be specified for connected segments" 

Environment

7.x

Cause

This issue occurs when there is an inconsistency in configuration between the OpenStack and NSX layers.

Resolution

1. Attach the VIO network to the router.
2. Disconnect the network.
3. Delete the network in VIO. 
4. If it fails, enable DHCP for the segment in NSX-T and then restart the neutron service and then try to attach the router, disconnect the network and try the deletion.