diff --git a/tempest/common/credentials_factory.py b/tempest/common/credentials_factory.py
index c6e5dcb..2d486a7 100644
--- a/tempest/common/credentials_factory.py
+++ b/tempest/common/credentials_factory.py
@@ -245,6 +245,9 @@
 
     if identity_version == 'v3':
         conf_attributes.append('domain_name')
+        conf_attributes.append('user_domain_name')
+        conf_attributes.append('project_domain_name')
+        conf_attributes.append('system')
     # Read the parts of credentials from config
     params = config.service_client_config()
     for attr in conf_attributes:
@@ -284,7 +287,8 @@
     if identity_version == 'v3':
         domain_fields = set(x for x in auth.KeystoneV3Credentials.ATTRIBUTES
                             if 'domain' in x)
-        if not domain_fields.intersection(kwargs.keys()):
+        if (not params.get('system') and
+                not domain_fields.intersection(kwargs.keys())):
             domain_name = CONF.auth.default_credentials_domain_name
             # NOTE(andreaf) Setting domain_name implicitly sets user and
             # project domain names, if they are None
diff --git a/tempest/config.py b/tempest/config.py
index 382b80f..7c4539c 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -92,7 +92,24 @@
     cfg.StrOpt('admin_domain_name',
                default='Default',
                help="Admin domain name for authentication (Keystone V3). "
-                    "The same domain applies to user and project"),
+                    "The same domain applies to user and project if "
+                    "admin_user_domain_name and admin_project_domain_name "
+                    "are not specified"),
+    cfg.StrOpt('admin_user_domain_name',
+               help="Domain name that contains the admin user (Keystone V3). "
+                    "May be different from admin_project_domain_name and "
+                    "admin_domain_name"),
+    cfg.StrOpt('admin_project_domain_name',
+               help="Domain name that contains the project given by "
+                    "admin_project_name (Keystone V3). May be different from "
+                    "admin_user_domain_name and admin_domain_name"),
+    cfg.StrOpt('admin_system',
+               default=None,
+               help="The system scope on which an admin user has an admin "
+                    "role assignment, if any. Valid values are 'all' or None. "
+                    "This must be set to 'all' if using the "
+                    "[oslo_policy]/enforce_scope=true option for the "
+                    "identity service."),
 ]
 
 identity_group = cfg.OptGroup(name='identity',
diff --git a/tempest/lib/auth.py b/tempest/lib/auth.py
index 7c279ab..9f8c7c5 100644
--- a/tempest/lib/auth.py
+++ b/tempest/lib/auth.py
@@ -428,7 +428,7 @@
 class KeystoneV3AuthProvider(KeystoneAuthProvider):
     """Provides authentication based on the Identity V3 API"""
 
-    SCOPES = set(['project', 'domain', 'unscoped', None])
+    SCOPES = set(['system', 'project', 'domain', 'unscoped', None])
 
     def _auth_client(self, auth_url):
         return json_v3id.V3TokenClient(
@@ -441,8 +441,8 @@
 
         Fields available in Credentials are passed to the token request,
         depending on the value of scope. Valid values for scope are: "project",
-        "domain". Any other string (e.g. "unscoped") or None will lead to an
-        unscoped token request.
+        "domain", or "system". Any other string (e.g. "unscoped") or None will
+        lead to an unscoped token request.
         """
 
         auth_params = dict(
@@ -465,12 +465,16 @@
                 domain_id=self.credentials.domain_id,
                 domain_name=self.credentials.domain_name)
 
+        if self.scope == 'system':
+            auth_params.update(system='all')
+
         return auth_params
 
     def _fill_credentials(self, auth_data_body):
-        # project or domain, depending on the scope
+        # project, domain, or system depending on the scope
         project = auth_data_body.get('project', None)
         domain = auth_data_body.get('domain', None)
+        system = auth_data_body.get('system', None)
         # user is always there
         user = auth_data_body['user']
         # Set project fields
@@ -490,6 +494,9 @@
                 self.credentials.domain_id = domain['id']
             if self.credentials.domain_name is None:
                 self.credentials.domain_name = domain['name']
+        # Set system scope
+        if system is not None:
+            self.credentials.system = 'all'
         # Set user fields
         if self.credentials.username is None:
             self.credentials.username = user['name']
@@ -677,7 +684,8 @@
                 raise exceptions.InvalidCredentials(msg)
         for key in attr:
             if key in self.ATTRIBUTES:
-                setattr(self, key, attr[key])
+                if attr[key] is not None:
+                    setattr(self, key, attr[key])
             else:
                 msg = '%s is not a valid attr for %s' % (key, self.__class__)
                 raise exceptions.InvalidCredentials(msg)
@@ -779,7 +787,7 @@
     ATTRIBUTES = ['domain_id', 'domain_name', 'password', 'username',
                   'project_domain_id', 'project_domain_name', 'project_id',
                   'project_name', 'tenant_id', 'tenant_name', 'user_domain_id',
-                  'user_domain_name', 'user_id']
+                  'user_domain_name', 'user_id', 'system']
     COLLISIONS = [('project_name', 'tenant_name'), ('project_id', 'tenant_id')]
 
     def __setattr__(self, key, value):
diff --git a/tempest/lib/common/cred_client.py b/tempest/lib/common/cred_client.py
index a81f53c..3af09a0 100644
--- a/tempest/lib/common/cred_client.py
+++ b/tempest/lib/common/cred_client.py
@@ -83,12 +83,15 @@
                       role['id'], project['id'], user['id'])
 
     @abc.abstractmethod
-    def get_credentials(self, user, project, password):
+    def get_credentials(
+            self, user, project, password, domain=None, system=None):
         """Produces a Credentials object from the details provided
 
         :param user: a user dict
-        :param project: a project dict
+        :param project: a project dict or None if using domain or system scope
         :param password: the password as a string
+        :param domain: a domain dict
+        :param system: a system dict
         :return: a Credentials object with all the available credential details
         """
         pass
@@ -116,7 +119,8 @@
     def delete_project(self, project_id):
         self.projects_client.delete_tenant(project_id)
 
-    def get_credentials(self, user, project, password):
+    def get_credentials(
+        self, user, project, password, domain=None, system=None):
         # User and project already include both ID and name here,
         # so there's no need to use the fill_in mode
         return auth.get_credentials(
@@ -156,23 +160,37 @@
     def delete_project(self, project_id):
         self.projects_client.delete_project(project_id)
 
-    def get_credentials(self, user, project, password):
+    def get_credentials(
+            self, user, project, password, domain=None, system=None):
         # User, project and domain already include both ID and name here,
         # so there's no need to use the fill_in mode.
         # NOTE(andreaf) We need to set all fields in the returned credentials.
         # Scope is then used to pick only those relevant for the type of
         # token needed by each service client.
+        if project:
+            project_name = project['name']
+            project_id = project['id']
+        else:
+            project_name = None
+            project_id = None
+        if domain:
+            domain_name = domain['name']
+            domain_id = domain['id']
+        else:
+            domain_name = self.creds_domain['name']
+            domain_id = self.creds_domain['id']
         return auth.get_credentials(
             auth_url=None,
             fill_in=False,
             identity_version='v3',
             username=user['name'], user_id=user['id'],
-            project_name=project['name'], project_id=project['id'],
+            project_name=project_name, project_id=project_id,
             password=password,
             project_domain_id=self.creds_domain['id'],
             project_domain_name=self.creds_domain['name'],
-            domain_id=self.creds_domain['id'],
-            domain_name=self.creds_domain['name'])
+            domain_id=domain_id,
+            domain_name=domain_name,
+            system=system)
 
     def assign_user_role_on_domain(self, user, role_name, domain=None):
         """Assign the specified role on a domain
diff --git a/tempest/lib/common/dynamic_creds.py b/tempest/lib/common/dynamic_creds.py
index 8b82391..0a2817b 100644
--- a/tempest/lib/common/dynamic_creds.py
+++ b/tempest/lib/common/dynamic_creds.py
@@ -142,7 +142,14 @@
         else:
             # We use a dedicated client manager for identity client in case we
             # need a different token scope for them.
-            scope = 'domain' if self.identity_admin_domain_scope else 'project'
+            if self.default_admin_creds.system:
+                scope = 'system'
+            elif (self.default_admin_creds.domain_id or
+                    self.default_admin_creds.domain_name or
+                    self.identity_admin_domain_scope):
+                scope = 'domain'
+            else:
+                scope = 'project'
             identity_os = clients.ServiceClients(self.default_admin_creds,
                                                  self.identity_uri,
                                                  scope=scope)
diff --git a/tempest/lib/services/identity/v3/token_client.py b/tempest/lib/services/identity/v3/token_client.py
index 6956297..08a8f46 100644
--- a/tempest/lib/services/identity/v3/token_client.py
+++ b/tempest/lib/services/identity/v3/token_client.py
@@ -51,7 +51,7 @@
     def auth(self, user_id=None, username=None, password=None, project_id=None,
              project_name=None, user_domain_id=None, user_domain_name=None,
              project_domain_id=None, project_domain_name=None, domain_id=None,
-             domain_name=None, token=None, app_cred_id=None,
+             domain_name=None, system=None, token=None, app_cred_id=None,
              app_cred_secret=None):
         """Obtains a token from the authentication service
 
@@ -65,6 +65,7 @@
         :param domain_name: a domain name to scope to
         :param project_id: a project id to scope to
         :param project_name: a project name to scope to
+        :param system: whether the token should be scoped to the system
         :param token: a token to re-scope.
 
         Accepts different combinations of credentials.
@@ -74,6 +75,7 @@
         - user_id, password
         - username, password, user_domain_id
         - username, password, project_name, user_domain_id, project_domain_id
+        - username, password, user_domain_id, system
         Validation is left to the server side.
         """
         creds = {
@@ -135,6 +137,8 @@
             creds['auth']['scope'] = dict(domain={'id': domain_id})
         elif domain_name:
             creds['auth']['scope'] = dict(domain={'name': domain_name})
+        elif system:
+            creds['auth']['scope'] = dict(system={system: True})
 
         body = json.dumps(creds, sort_keys=True)
         resp, body = self.post(self.auth_url, body=body)
diff --git a/tempest/tests/common/test_credentials_factory.py b/tempest/tests/common/test_credentials_factory.py
index 0ef3742..374474d 100644
--- a/tempest/tests/common/test_credentials_factory.py
+++ b/tempest/tests/common/test_credentials_factory.py
@@ -173,10 +173,15 @@
     @mock.patch.object(cf, 'get_credentials')
     def test_get_configured_admin_credentials(self, mock_get_credentials):
         cfg.CONF.set_default('auth_version', 'v3', 'identity')
-        all_params = [('admin_username', 'username', 'my_name'),
-                      ('admin_password', 'password', 'secret'),
-                      ('admin_project_name', 'project_name', 'my_pname'),
-                      ('admin_domain_name', 'domain_name', 'my_dname')]
+        all_params = [
+            ('admin_username', 'username', 'my_name'),
+            ('admin_user_domain_name', 'user_domain_name', 'my_dname'),
+            ('admin_password', 'password', 'secret'),
+            ('admin_project_name', 'project_name', 'my_pname'),
+            ('admin_project_domain_name', 'project_domain_name', 'my_dname'),
+            ('admin_domain_name', 'domain_name', 'my_dname'),
+            ('admin_system', 'system', None),
+        ]
         expected_result = 'my_admin_credentials'
         mock_get_credentials.return_value = expected_result
         for config_item, _, value in all_params:
@@ -194,10 +199,15 @@
     def test_get_configured_admin_credentials_not_fill_valid(
             self, mock_get_credentials):
         cfg.CONF.set_default('auth_version', 'v2', 'identity')
-        all_params = [('admin_username', 'username', 'my_name'),
-                      ('admin_password', 'password', 'secret'),
-                      ('admin_project_name', 'project_name', 'my_pname'),
-                      ('admin_domain_name', 'domain_name', 'my_dname')]
+        all_params = [
+            ('admin_username', 'username', 'my_name'),
+            ('admin_user_domain_name', 'user_domain_name', 'my_dname'),
+            ('admin_password', 'password', 'secret'),
+            ('admin_project_domain_name', 'project_domain_name', 'my_dname'),
+            ('admin_project_name', 'project_name', 'my_pname'),
+            ('admin_domain_name', 'domain_name', 'my_dname'),
+            ('admin_system', 'system', None),
+        ]
         expected_result = mock.Mock()
         expected_result.is_valid.return_value = True
         mock_get_credentials.return_value = expected_result
@@ -278,3 +288,20 @@
         mock_auth_get_credentials.assert_called_once_with(
             expected_uri, fill_in=False, identity_version='v3',
             **expected_params)
+
+    @mock.patch('tempest.lib.auth.get_credentials')
+    def test_get_credentials_v3_system(self, mock_auth_get_credentials):
+        expected_uri = 'V3_URI'
+        expected_result = 'my_creds'
+        mock_auth_get_credentials.return_value = expected_result
+        cfg.CONF.set_default('uri_v3', expected_uri, 'identity')
+        cfg.CONF.set_default('admin_system', 'all', 'auth')
+        params = {'system': 'all'}
+        expected_params = params.copy()
+        expected_params.update(config.service_client_config())
+        result = cf.get_credentials(fill_in=False, identity_version='v3',
+                                    **params)
+        self.assertEqual(expected_result, result)
+        mock_auth_get_credentials.assert_called_once_with(
+            expected_uri, fill_in=False, identity_version='v3',
+            **expected_params)
diff --git a/tempest/tests/lib/common/test_cred_client.py b/tempest/tests/lib/common/test_cred_client.py
index 860a465..b99311c 100644
--- a/tempest/tests/lib/common/test_cred_client.py
+++ b/tempest/tests/lib/common/test_cred_client.py
@@ -43,6 +43,14 @@
         self.projects_client.delete_tenant.assert_called_once_with(
             'fake_id')
 
+    def test_get_credentials(self):
+        ret = self.creds_client.get_credentials(
+            {'name': 'some_user', 'id': 'fake_id'},
+            {'name': 'some_project', 'id': 'fake_id'},
+            'password123')
+        self.assertEqual(ret.username, 'some_user')
+        self.assertEqual(ret.project_name, 'some_project')
+
 
 class TestCredClientV3(base.TestCase):
     def setUp(self):
@@ -53,7 +61,7 @@
         self.roles_client = mock.MagicMock()
         self.domains_client = mock.MagicMock()
         self.domains_client.list_domains.return_value = {
-            'domains': [{'id': 'fake_domain_id'}]
+            'domains': [{'id': 'fake_domain_id', 'name': 'some_domain'}]
         }
         self.creds_client = cred_client.V3CredsClient(self.identity_client,
                                                       self.projects_client,
@@ -75,3 +83,31 @@
         self.creds_client.delete_project('fake_id')
         self.projects_client.delete_project.assert_called_once_with(
             'fake_id')
+
+    def test_get_credentials(self):
+        ret = self.creds_client.get_credentials(
+            {'name': 'some_user', 'id': 'fake_id'},
+            {'name': 'some_project', 'id': 'fake_id'},
+            'password123')
+        self.assertEqual(ret.username, 'some_user')
+        self.assertEqual(ret.project_name, 'some_project')
+        self.assertIsNone(ret.system)
+        self.assertEqual(ret.domain_name, 'some_domain')
+        ret = self.creds_client.get_credentials(
+            {'name': 'some_user', 'id': 'fake_id'},
+            None,
+            'password123',
+            domain={'name': 'another_domain', 'id': 'another_id'})
+        self.assertEqual(ret.username, 'some_user')
+        self.assertIsNone(ret.project_name)
+        self.assertIsNone(ret.system)
+        self.assertEqual(ret.domain_name, 'another_domain')
+        ret = self.creds_client.get_credentials(
+            {'name': 'some_user', 'id': 'fake_id'},
+            None,
+            'password123',
+            system={'system': 'all'})
+        self.assertEqual(ret.username, 'some_user')
+        self.assertIsNone(ret.project_name)
+        self.assertEqual(ret.system, {'system': 'all'})
+        self.assertEqual(ret.domain_name, 'some_domain')
diff --git a/tempest/tests/lib/test_auth.py b/tempest/tests/lib/test_auth.py
index c3a792f..3edb122 100644
--- a/tempest/tests/lib/test_auth.py
+++ b/tempest/tests/lib/test_auth.py
@@ -786,6 +786,19 @@
                 self.assertIn(attr, auth_params.keys())
                 self.assertEqual(getattr(all_creds, attr), auth_params[attr])
 
+    def test_auth_parameters_with_system_scope(self):
+        all_creds = fake_credentials.FakeKeystoneV3AllCredentials()
+        self.auth_provider.credentials = all_creds
+        self.auth_provider.scope = 'system'
+        auth_params = self.auth_provider._auth_params()
+        self.assertNotIn('scope', auth_params.keys())
+        for attr in all_creds.get_init_attributes():
+            if attr.startswith('project_') or attr.startswith('domain_'):
+                self.assertNotIn(attr, auth_params.keys())
+            else:
+                self.assertIn(attr, auth_params.keys())
+                self.assertEqual(getattr(all_creds, attr), auth_params[attr])
+
 
 class TestKeystoneV3Credentials(base.TestCase):
     def testSetAttrUserDomain(self):