diff --git a/tempest/api/compute/servers/test_attach_interfaces.py b/tempest/api/compute/servers/test_attach_interfaces.py
index ac18442..ae172b8 100644
--- a/tempest/api/compute/servers/test_attach_interfaces.py
+++ b/tempest/api/compute/servers/test_attach_interfaces.py
@@ -108,21 +108,24 @@
         """
         port = self.ports_client.show_port(port_id)['port']
         device_id = port['device_id']
+        dns_name = port.get('dns_name')
         start = int(time.time())
 
         # NOTE(mriedem): Nova updates the port's device_id to '' rather than
         # None, but it's not contractual so handle Falsey either way.
-        while device_id:
+        while any([device_id, dns_name]):
             time.sleep(self.build_interval)
             port = self.ports_client.show_port(port_id)['port']
             device_id = port['device_id']
+            dns_name = port.get('dns_name')
 
             timed_out = int(time.time()) - start >= self.build_timeout
 
-            if device_id and timed_out:
-                message = ('Port %s failed to detach (device_id %s) within '
-                           'the required time (%s s).' %
-                           (port_id, device_id, self.build_timeout))
+            if any([device_id, dns_name]) and timed_out:
+                message = ('Port %s failed to detach (device_id %s), '
+                           '(dns_name %s) within the required time (%s s).' %
+                           (port_id, device_id or 'is out',
+                            dns_name or 'is out', self.build_timeout))
                 raise lib_exc.TimeoutException(message)
 
         return port
diff --git a/tempest/api/compute/test_quotas.py b/tempest/api/compute/test_quotas.py
index 5fe0e3b..33f681b 100644
--- a/tempest/api/compute/test_quotas.py
+++ b/tempest/api/compute/test_quotas.py
@@ -13,11 +13,16 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import testtools
+
 from tempest.api.compute import base
 from tempest.common import tempest_fixtures as fixtures
 from tempest.common import utils
+from tempest import config
 from tempest.lib import decorators
 
+CONF = config.CONF
+
 
 class QuotasTestJSON(base.BaseV2ComputeTest):
     """Test compute quotas"""
@@ -84,6 +89,8 @@
         for quota in expected_quota_set:
             self.assertIn(quota, quota_set.keys())
 
+    @testtools.skipIf(not CONF.auth.use_dynamic_credentials,
+                      'does not support static credentials')
     @decorators.idempotent_id('cd65d997-f7e4-4966-a7e9-d5001b674fdc')
     def test_compare_tenant_quotas_with_default_quotas(self):
         """Test tenants are created with the default compute quota values"""
diff --git a/tempest/api/network/test_tags.py b/tempest/api/network/test_tags.py
index 5219c34..e93e75a 100644
--- a/tempest/api/network/test_tags.py
+++ b/tempest/api/network/test_tags.py
@@ -111,7 +111,10 @@
 
     # NOTE(felipemonteiro): The supported resource names are plural. Use
     # the singular case for the corresponding class resource object.
-    SUPPORTED_RESOURCES = ['subnets', 'ports', 'routers', 'subnetpools']
+    if config.is_tungstenfabric_backend_enabled():
+        SUPPORTED_RESOURCES = ['subnets', 'ports', 'routers']
+    else:
+        SUPPORTED_RESOURCES = ['subnets', 'ports', 'routers', 'subnetpools']
 
     @classmethod
     def skip_checks(cls):
@@ -132,6 +135,9 @@
         cls.port = cls.create_port(cls.network)
         cls.router = cls.create_router()
 
+        if config.is_tungstenfabric_backend_enabled():
+            return
+
         subnetpool_name = data_utils.rand_name(cls.__name__ + '-Subnetpool')
         prefix = CONF.network.default_network
         cls.subnetpool = cls.subnetpools_client.create_subnetpool(
diff --git a/tempest/config.py b/tempest/config.py
index 7a9d19b..2eadea0 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1607,6 +1607,17 @@
     return _parameters
 
 
+def is_tungstenfabric_backend_enabled():
+    """Return True if TungstenFabric is used as a backend."""
+    try:
+        sdn = getattr(CONF, 'sdn')
+        service_name = getattr(sdn, 'service_name')
+        if service_name == 'tungstenfabric':
+            return True
+    except cfg.NoSuchOptError:
+        return False
+
+
 def _register_tempest_service_clients():
     # Register tempest own service clients using the same mechanism used
     # for external plugins.
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 39d6e38..39021d5 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -1066,7 +1066,6 @@
                                             private_key=private_key,
                                             server=server,
                                             username=username)
-        self.check_vm_connectivity(ip_address)
 
         if dev_name is not None:
             ssh_client.make_fs(dev_name, fs=fs)
@@ -1100,8 +1099,6 @@
                                             server=server,
                                             username=username)
 
-        self.check_vm_connectivity(ip_address)
-
         if dev_name is not None:
             ssh_client.mount(dev_name, mount_path)
         timestamp = ssh_client.exec_command('sudo cat %s/timestamp'