Comment 2 for bug 1888395

this does not appear to be a nova bug.

i am still waiting for the reporter to clarify what network backedn driver they are using
but i suspect its the networking_opencontrail ml2 driver

https://opendev.org/x/networking-opencontrail/src/branch/master/networking_opencontrail/ml2/mech_driver.py#L35

the opencontrial ml2 driver does not implement supported_extensions
so the default implemenation which retruns all exentions is used
https://github.com/openstack/neutron-lib/blob/96e1d028b84419d187f085b587e672447df00ae3/neutron_lib/plugins/ml2/api.py#L458-L471

as a result support for the 'binding-extended' extension
https://github.com/openstack/neutron-lib/blob/master/neutron_lib/api/definitions/portbindings_extended.py
is likely incorrectly being reported

can you povide the our put of "openstack extension list | grep binding" to confirm

the only extion that should be listed is

| Port Binding | binding | Expose port bindings of a virtual port to external application

the following one should not be present on a deployment using netwroking-opencontial since it does not support it

| Port Bindings Extended | binding-extended | Expose port bindings of a virtual port to external application

but based on the behaviour we are seeing it seams this is not the case.

can you confirm?