The Group IP members API GET:/infra/domains/{domain-id}/groups/{group-id}/members/ip-addresses returns a status code 400 - Bad Request Response when a group is in the failed state, and the failed group status is reported in the GUI and not via the API.
https://developer.broadcom.com/xapis/nsx-t-data-center-rest-api/4.2.2/method_GetGroupIPMembers.html
The HTTP status 400 Bad Request is not a valid response status code, as the API request sent is valid.
VMware NSX-T 4.x
When the internal connectivity between the NSX-T Proton and CCP services is broken, the API GET:/infra/domains/{domain-id}/groups/{group-id}/members/ip-addresses returns a HTTP status code 400.
Ideal behavior is to return the 5xx HTTP status code.
From NSX-T 9.0 onwards, this behavior correction is made to return a Server error (5xx) instead of a misleading 400 for the scenarios where the Proton to CCP RPC channel communication is broken.
The server will return the HTTP error code of 500 along with the response message *similar* to the one below:
{ "httpStatus": "INTERNAL_SERVER_ERROR", "error_code": 500702, "module_name": "policy", "error_message": "Error while getting membership for the Group /infra/domains/default/groups/<group-id> from enforcement point /infra/sites/default/enforcement-points/default. Connectivity issue between Policy and CCP services. More details: - Server is temporarily unable to handle the request. Please check health of the cluster."}