diff --git a/tempest/api/network/base.py b/tempest/api/network/base.py
index 91e3e14..f1f0b08 100644
--- a/tempest/api/network/base.py
+++ b/tempest/api/network/base.py
@@ -152,33 +152,35 @@
         return network
 
     @classmethod
-    def create_subnet(cls, network, gateway=None, cidr=None, mask_bits=None,
-                      **kwargs):
+    def create_subnet(cls, network, gateway='', cidr=None, mask_bits=None,
+                      ip_version=None, **kwargs):
         """Wrapper utility that returns a test subnet."""
         # The cidr and mask_bits depend on the ip version.
-        if cls._ip_version == 4:
+        ip_version = ip_version if ip_version is not None else cls._ip_version
+        gateway_not_set = gateway == ''
+        if ip_version == 4:
             cidr = cidr or netaddr.IPNetwork(CONF.network.tenant_network_cidr)
             mask_bits = mask_bits or CONF.network.tenant_network_mask_bits
-        elif cls._ip_version == 6:
+        elif ip_version == 6:
             cidr = (
                 cidr or netaddr.IPNetwork(CONF.network.tenant_network_v6_cidr))
             mask_bits = mask_bits or CONF.network.tenant_network_v6_mask_bits
         # Find a cidr that is not in use yet and create a subnet with it
         for subnet_cidr in cidr.subnet(mask_bits):
-            if not gateway:
-                gateway = str(netaddr.IPAddress(subnet_cidr) + 1)
+            if gateway_not_set:
+                gateway_ip = str(netaddr.IPAddress(subnet_cidr) + 1)
+            else:
+                gateway_ip = gateway
             try:
                 resp, body = cls.client.create_subnet(
                     network_id=network['id'],
                     cidr=str(subnet_cidr),
-                    ip_version=cls._ip_version,
-                    gateway_ip=gateway,
+                    ip_version=ip_version,
+                    gateway_ip=gateway_ip,
                     **kwargs)
                 break
             except exceptions.BadRequest as e:
                 is_overlapping_cidr = 'overlaps with another subnet' in str(e)
-                # Unset gateway value if there is an overlapping subnet
-                gateway = None
                 if not is_overlapping_cidr:
                     raise
         else:
diff --git a/tempest/api/network/test_networks.py b/tempest/api/network/test_networks.py
index 986a2c8..dd81a09 100644
--- a/tempest/api/network/test_networks.py
+++ b/tempest/api/network/test_networks.py
@@ -280,6 +280,10 @@
         self.subnets.pop()
 
     @test.attr(type='smoke')
+    def test_create_delete_subnet_without_gateway(self):
+        self._create_verify_delete_subnet()
+
+    @test.attr(type='smoke')
     def test_create_delete_subnet_with_gw(self):
         self._create_verify_delete_subnet(
             **self.subnet_dict(['gateway']))
@@ -492,7 +496,7 @@
         self.assertEqual(subnet['gateway_ip'], gateway)
 
     @test.attr(type='smoke')
-    def test_create_delete_subnet_without_gw(self):
+    def test_create_delete_subnet_with_default_gw(self):
         net = netaddr.IPNetwork(CONF.network.tenant_network_v6_cidr)
         gateway_ip = str(netaddr.IPAddress(net.first + 1))
         name = data_utils.rand_name('network-')
@@ -501,16 +505,62 @@
         # Verifies Subnet GW in IPv6
         self.assertEqual(subnet['gateway_ip'], gateway_ip)
 
+    @test.attr(type='smoke')
+    def test_create_list_subnet_with_no_gw64_one_network(self):
+        name = data_utils.rand_name('network-')
+        network = self.create_network(name)
+        ipv6_gateway = self.subnet_dict(['gateway'])['gateway']
+        subnet1 = self.create_subnet(network,
+                                     ip_version=6,
+                                     gateway=ipv6_gateway)
+        self.assertEqual(netaddr.IPNetwork(subnet1['cidr']).version, 6,
+                         'The created subnet is not IPv6')
+        subnet2 = self.create_subnet(network,
+                                     gateway=None,
+                                     ip_version=4)
+        self.assertEqual(netaddr.IPNetwork(subnet2['cidr']).version, 4,
+                         'The created subnet is not IPv4')
+        # Verifies Subnet GW is set in IPv6
+        self.assertEqual(subnet1['gateway_ip'], ipv6_gateway)
+        # Verifies Subnet GW is None in IPv4
+        self.assertEqual(subnet2['gateway_ip'], None)
+        # Verifies all 2 subnets in the same network
+        _, body = self.client.list_subnets()
+        subnets = [sub['id'] for sub in body['subnets']
+                   if sub['network_id'] == network['id']]
+        test_subnet_ids = [sub['id'] for sub in (subnet1, subnet2)]
+        self.assertItemsEqual(subnets,
+                              test_subnet_ids,
+                              'Subnet are not in the same network')
+
     @testtools.skipUnless(CONF.network_feature_enabled.ipv6_subnet_attributes,
                           "IPv6 extended attributes for subnets not "
                           "available")
     @test.attr(type='smoke')
-    def test_create_delete_subnet_with_v6_attributes(self):
+    def test_create_delete_subnet_with_v6_attributes_stateful(self):
         self._create_verify_delete_subnet(
             gateway=self._subnet_data[self._ip_version]['gateway'],
+            ipv6_ra_mode='dhcpv6-stateful',
+            ipv6_address_mode='dhcpv6-stateful')
+
+    @testtools.skipUnless(CONF.network_feature_enabled.ipv6_subnet_attributes,
+                          "IPv6 extended attributes for subnets not "
+                          "available")
+    @test.attr(type='smoke')
+    def test_create_delete_subnet_with_v6_attributes_slaac(self):
+        self._create_verify_delete_subnet(
             ipv6_ra_mode='slaac',
             ipv6_address_mode='slaac')
 
+    @testtools.skipUnless(CONF.network_feature_enabled.ipv6_subnet_attributes,
+                          "IPv6 extended attributes for subnets not "
+                          "available")
+    @test.attr(type='smoke')
+    def test_create_delete_subnet_with_v6_attributes_stateless(self):
+        self._create_verify_delete_subnet(
+            ipv6_ra_mode='dhcpv6-stateless',
+            ipv6_address_mode='dhcpv6-stateless')
+
 
 class NetworksIpV6TestXML(NetworksIpV6TestJSON):
     _interface = 'xml'