Comment 3 for bug 1743425

I can pretty much reproduce this at will now.

steps:

with a working installation of neutron, edit /etc/neutron/plugins/ml2/ml2_conf.ini

change network_vlan_ranges= xxx to anything else. invent a new network and put it in here

then in /etc/neutron/plugins/ml2/openvswitch_agent change

bridge_mappings= old_br_name to

bridge_mappings= new_br_name

Then restart neutron-server and it will fail.

Change the values back to their previous values and it will start.
Even if you delete the networks from neutron/openstack it still won't allow you to change them.

How am I supposed to remove the vlan mapping and bridge mapping for networks I've deleted ? It seems to want to keep them in the config file or else it will result in neutron spitting out the error UnmappedInstanceError: Class 'neutron.objects.plugins.ml2.vlanallocation.VlanAllocation' is not mapped