Is it possible to back port it to Liberty? We are having this issue often:

2016-02-12 18:38:27.867 121291 WARNING neutron.agent.metadata.agent [-] Server does not support metadata RPC, fallback to using neutron client
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent [-] Unexpected error.
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent Traceback (most recent call last):
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 114, in __call__
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     instance_id, tenant_id = self._get_instance_and_tenant_id(req)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 210, in _get_instance_and_tenant_id
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     ports = self._get_ports(remote_address, network_id, router_id)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 198, in _get_ports
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     networks = self._get_router_networks(router_id)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/common/utils.py", line 104, in __call__
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     return self._get_from_cache(target_self, *args, **kwargs)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/common/utils.py", line 82, in _get_from_cache
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     item = self.func(target_self, *args, **kwargs)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 159, in _get_router_networks
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     internal_ports = self._get_ports_from_server(router_id=router_id)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 141, in _get_ports_from_server
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     return self._get_ports_using_client(filters)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutron/agent/metadata/agent.py", line 183, in _get_ports_using_client
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     ports = client.list_ports(**filters)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 102, in with_params
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     ret = self.function(instance, *args, **kwargs)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 547, in list_ports
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     **_params)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 307, in list
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     for r in self._pagination(collection, path, **params):
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 320, in _pagination
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     res = self.get(path, params=params)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 293, in get
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     headers=headers, params=params)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 270, in retry_request
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     headers=headers, params=params)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 200, in do_request
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     content_type=self.content_type())
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 158, in do_request
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     self.authenticate_and_fetch_endpoint_url()
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 123, in authenticate_and_fetch_endpoint_url
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     self.authenticate()
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 237, in authenticate
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     self._authenticate_keystone()
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent   File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 218, in _authenticate_keystone
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent     raise exceptions.Unauthorized(message=resp_body)
2016-02-12 18:38:27.871 121286 ERROR neutron.agent.metadata.agent Unauthorized: {"error": {"message": "The resource could not be found.", "code": 404, "title": "Not Found"}}

In neutron.conf we have:

auth_url = http://IP:35357

And it seems it just gets 404 due to there is no such URL http://IP:35357/tokens, it should be http://IP:35357/v2.0/tokens but in /usr/lib/python2.7/site-packages/neutronclient/client.py it is hard coded 'token_url = self.auth_url + "/tokens"'