Description of problem: If a VM is attached to the parent network port of a trunk and the VM is deleted, the trunk and port become undeletable through normal OpenStack commands. When these are part of a stack, attempting to delete the stack will also consequently fail . Running the following query against the overcloud DB has been useful to quickly identify such problematic situations where the VM has been previously deleted . SELECT ports.id as port_id, ports.device_id as instance_id ,ports.status as port_status, ml2pb.status as binding_status, ml2pb.vif_type, ml2pb.vnic_type, ont.id AS trunk_id, ont.status as trunk_status , ml2pb.vif_details FROM ovs_neutron.ports ports, ovs_neutron.ml2_port_bindings ml2pb , ovs_neutron.trunks ont where ports.id=ml2pb.port_id AND ml2pb.port_id=ont.port_id AND ports.device_id!='' AND (ports.device_id NOT IN (select uuid from nova.instances) OR ports.device_id IN (select uuid from nova.instances where vm_state='deleted')) \G Version-Release number of selected component (if applicable): OpenStack 16.1 and 16.2 . Similar issues for OSP 13 and 16.x reported in BZ 1812433 How reproducible: If the steps below are followed, it should be consistently reproducible. Though all recent customer cases reported have been opened with the VM already deleted (step 2 below), it is not certain that step 2 will always be successful, based on previous similar cases referenced in BZ 1812433 . Steps to Reproduce: 1.Spawn a tenant stack with a trunk whose parent port has a VM attached to it 2.Delete the aforementioned VM 3.Try to Delete the stack Actual results: While attempting stack deletion, we get a failure for reason [1] which is correlated with [2] in Neutron logs . Manually deleting the port via OpenStack CLI fails with [3]. Manually deleting the trunk via OpenStack CLI fails with [4]. [1] " Conflict: resources.[obfuscated]-L-HP-X-01-trunk-parent-TRUNK-VIO-v6-instance02_Provider_Trunk: Trunk [obfuscated] is currently in use " [2] "Trunk driver does not consider trunk [obfuscated] untrunkable" [3] Failed to delete port with name or ID [obfuscated]: ConflictException: 409: Client Error for url: http://[obfuscated] is currently a parent port for trunk [obfuscated]. 1 of 1 ports failed to delete. [4] Failed to delete trunk with name or ID [obfuscated]: Trunk [obfuscated] is currently in use. Neutron server returns request_ids: [[obfuscated]] Expected results: Stack and associated trunks and ports delete successfully Additional info: Multiple customer cases have been reported very recently and fixed through article https://access.redhat.com/solutions/6826221 and previously through https://access.redhat.com/solutions/4993961 See also previous BZ https://bugzilla.redhat.com/show_bug.cgi?id=1812433