Openstack installation on ubuntu. Neutron connection issue

I try to configure on a single node openstack by following this tutorial: http://docs.openstack.org/juno/install-guide/install/apt/content/neutron-controller-node.html

My installation is done in a Virtual Machine.

My /etc/hosts is:

root@openstack:~/openstack# cat /etc/hosts
127.0.0.1   localhost
127.0.0.1   openstack
127.0.0.1   controller  
127.0.0.1   network
127.0.0.1   compute1

I passed with success all the steps until the neutron installation: http://docs.openstack.org/juno/install-guide/install/apt/content/neutron-controller-node.html

I have a connection issue with neutron:

root@openstack:~/openstack# neutron ext-list
Unable to establish connection to http://controller:9696/v2.0/extensions.json

When I activate the debug option I have the following trace:

root@openstack:~/openstack# neutron ext-list --debug
DEBUG: keystoneclient.session REQ: curl -i -X GET http://controller:35357/v2.0 -H "Accept: application/json" -H "User-Agent: python-keystoneclient"
DEBUG: keystoneclient.session RESP: [200] {'date': 'Mon, 15 Dec 2014 16:59:05 GMT', 'vary': 'X-Auth-Token', 'content-length': '421', 'content-type': 'application/json', 'x-distribution': 'Ubuntu'} 
RESP BODY: {"version": {"status": "stable", "updated": "2014-04-17T00:00:00Z", "media-types": [{"base": "application/json", "type": "application/vnd.openstack.identity-v2.0+json"}, {"base": "application/xml", "type": "application/vnd.openstack.identity-v2.0+xml"}], "id": "v2.0", "links": [{"href": "http://controller:35357/v2.0/", "rel": "self"}, {"href": "http://docs.openstack.org/", "type": "text/html", "rel": "describedby"}]}}

DEBUG: stevedore.extension found extension EntryPoint.parse('table = cliff.formatters.table:TableFormatter')
DEBUG: stevedore.extension found extension EntryPoint.parse('csv = cliff.formatters.commaseparated:CSVLister')
DEBUG: neutronclient.neutron.v2_0.extension.ListExt get_data(Namespace(columns=[], fields=[], formatter='table', max_width=0, quote_mode='nonnumeric', request_format='json', show_details=False))
DEBUG: keystoneclient.auth.identity.v2 Making authentication request to http://controller:35357/v2.0/tokens
DEBUG: keystoneclient.session REQ: curl -i -X GET http://controller:9696/v2.0/extensions.json -H "User-Agent: python-neutronclient" -H "Accept: application/json" -H "X-Auth-Token: ded80764051740a58da4bb80543cd69f"
ERROR: neutronclient.shell Unable to establish connection to http://controller:9696/v2.0/extensions.json
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/neutronclient/shell.py", line 691, in run_subcommand
    return run_command(cmd, cmd_parser, sub_argv)
  File "/usr/lib/python2.7/dist-packages/neutronclient/shell.py", line 90, in run_command
    return cmd.run(known_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/common/command.py", line 29, in run
    return super(OpenStackCommand, self).run(parsed_args)
  File "/usr/lib/python2.7/dist-packages/cliff/display.py", line 91, in run
    column_names, data = self.take_action(parsed_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/common/command.py", line 35, in take_action
    return self.get_data(parsed_args)
  File "/usr/lib/python2.7/dist-packages/neutronclient/neutron/v2_0/__init__.py", line 669, in get_data
    data = self.retrieve_list(parsed_args)
  File "/usr/lib/python2.7/dist-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/dist-packages/neutronclient/neutron/v2_0/__init__.py", line 610, in call_server
    data = obj_lister(**search_opts)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 99, in with_params
    ret = self.function(instance, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 301, in list_extensions
    return self.get(self.extensions_path, params=_params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 1321, in get
    headers=headers, params=params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 1298, in retry_request
    headers=headers, params=params)
  File "/usr/lib/python2.7/dist-packages/neutronclient/v2_0/client.py", line 1241, in do_request
    content_type=self.content_type())
  File "/usr/lib/python2.7/dist-packages/neutronclient/client.py", line 319, in do_request
    return self.request(url, method, **kwargs)
  File "/usr/lib/python2.7/dist-packages/neutronclient/client.py", line 63, in request
    return self._request(url, method, body=body, headers=headers, **kwargs)
  File "/usr/lib/python2.7/dist-packages/neutronclient/client.py", line 314, in _request
    **kwargs)
  File "/usr/lib/python2.7/dist-packages/keystoneclient/utils.py", line 318, in inner
    return func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/keystoneclient/session.py", line 324, in request
    resp = self._send_request(url, method, redirect, log, **kwargs)
  File "/usr/lib/python2.7/dist-packages/keystoneclient/session.py", line 359, in _send_request
    raise exceptions.ConnectionRefused(msg)
ConnectionRefused: Unable to establish connection to http://controller:9696/v2.0/extensions.json
Unable to establish connection to http://controller:9696/v2.0/extensions.json

Do you know what could be the issue?