getting "Unable to connect to Neutron" error from Horizon. Also `neutron floatingip-list` is failing with 404 error.

Issue

• neutron floatingip-list command fails with an error:

[root@dhcp209-220 ~(keystone_admin)]# neutron floatingip-list
Not Found (HTTP 404) (Request-ID: req-ca200c33-3b22-48ac-8441-211685a73134)

[root@control1 keystone]# neutron floatingip-list --debug
[...]
DEBUG: keystoneclient.session REQ: curl -i -X GET http://xx.xx.xx.xx:9696/v2.0/floatingips.json -H "User-Agent: python-neutronclient" -H "Accept: application/json" -H

"X-Auth-Token: TOKEN_REDACTED"
DEBUG: keystoneclient.session RESP:
DEBUG: keystoneclient.session Request returned failure status: 404  <========
ERROR: neutronclient.shell Not Found (HTTP 404) (Request-ID: req-b89915b4-b398-449c-b198-f4367aaaa6cf)  <=======
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/neutronclient/shell.py", line 691, in run_subcommand
    return run_command(cmd, cmd_parser, sub_argv)
  File "/usr/lib/python2.7/site-packages/neutronclient/shell.py", line 90, in run_command
    return cmd.run(known_args)
  File "/usr/lib/python2.7/site-packages/neutronclient/common/command.py", line 29, in run
    return super(OpenStackCommand, self).run(parsed_args)
  File "/usr/lib/python2.7/site-packages/cliff/display.py", line 91, in run
    column_names, data = self.take_action(parsed_args)
  File "/usr/lib/python2.7/site-packages/neutronclient/common/command.py", line 35, in take_action
    return self.get_data(parsed_args)
  File "/usr/lib/python2.7/site-packages/neutronclient/neutron/v2_0/__init__.py", line 669, in get_data
    data = self.retrieve_list(parsed_args)
  File "/usr/lib/python2.7/site-packages/neutronclient/neutron/v2_0/__init__.py", line 638, in retrieve_list
    data = self.call_server(neutron_client, search_opts, parsed_args)
  File "/usr/lib/python2.7/site-packages/neutronclient/neutron/v2_0/__init__.py", line 610, in call_server
    data = obj_lister(**search_opts)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 98, in with_params
    ret = self.function(instance, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 443, in list_floatingips
    **_params)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 1334, in list
    for r in self._pagination(collection, path, **params):
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 1347, in _pagination
    res = self.get(path, params=params)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 1320, in get
    headers=headers, params=params)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 1297, in retry_request
    headers=headers, params=params)
  File "/usr/lib/python2.7/site-packages/neutronclient/v2_0/client.py", line 1240, in do_request
    content_type=self.content_type())
  File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 319, in do_request
    return self.request(url, method, **kwargs)
  File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 63, in request
    return self._request(url, method, body=body, headers=headers, **kwargs)
  File "/usr/lib/python2.7/site-packages/neutronclient/client.py", line 314, in _request
    **kwargs)
  File "/usr/lib/python2.7/site-packages/keystoneclient/utils.py", line 318, in inner
    return func(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/keystoneclient/session.py", line 346, in request
    raise exceptions.from_response(resp, method, url)
NotFound: Not Found (HTTP 404) (Request-ID: req-b89915b4-b398-449c-b198-f4367aaaa6cf)
Not Found (HTTP 404) (Request-ID: req-b89915b4-b398-449c-b198-f4367aaaa6cf)
[...]

• From /var/log/neutron/server.log

[root@dhcp210-126 01463878]# grep -i req-b89915b4-b398-449c-b198-f4367aaaa6cf 990-control3_server.log
2015-07-17 08:51:44.947 5646 DEBUG routes.middleware [req-b89915b4-b398-449c-b198-f4367aaaa6cf ] No route matched for GET /floatingips.json __call__ /usr/lib/python2.7/site-packages/routes/middleware.py:97
2015-07-17 08:51:44.947 5646 DEBUG routes.middleware [req-b89915b4-b398-449c-b198-f4367aaaa6cf ] No route matched for GET /floatingips.json __call__ /usr/lib/python2.7/site-packages/routes/middleware.py:97
2015-07-17 08:51:44.948 5646 INFO neutron.wsgi [req-b89915b4-b398-449c-b198-f4367aaaa6cf None] xx.xx.xx.xx - - [17/Jul/2015 08:51:44] "GET /v2.0/floatingips.json HTTP/1.1" 404 242 0.039737