diff --git a/magnum/api/attr_validator.py b/magnum/api/attr_validator.py
index 46386ecd78..03278859a3 100644
--- a/magnum/api/attr_validator.py
+++ b/magnum/api/attr_validator.py
@@ -99,9 +99,23 @@ def validate_external_network(cli, external_network):
 def validate_fixed_network(cli, fixed_network):
     """Validate fixed network"""
 
-    # TODO(houming):this method implement will be added after this
-    # first pathch for Cluster's OpenStack resources validation is merged.
-    pass
+    count = 0
+    network_id = None
+    networks = cli.neutron().list_networks()
+    for net in networks.get('networks'):
+        if fixed_network in [net.get('name'), net.get('id')]:
+            count += 1
+            network_id = net.get('id')
+
+    if count == 0:
+        # Unable to find the configured fixed_network.
+        raise exception.FixedNetworkNotFound(network=fixed_network)
+    elif count > 1:
+        msg = _("Multiple networks exist with same name '%s'. "
+                "Please use the network ID instead.")
+        raise exception.Conflict(msg % fixed_network)
+
+    return network_id
 
 
 def validate_labels(labels):
diff --git a/magnum/tests/unit/api/test_attr_validator.py b/magnum/tests/unit/api/test_attr_validator.py
index 9e43281885..d5b7c05a7a 100644
--- a/magnum/tests/unit/api/test_attr_validator.py
+++ b/magnum/tests/unit/api/test_attr_validator.py
@@ -94,6 +94,44 @@ class TestAttrValidator(base.BaseTestCase):
                           attr_validator.validate_external_network,
                           mock_os_cli, 'test_ext_net')
 
+    def test_validate_fixed_network_with_valid_network(self):
+        mock_networks = {'networks': [{'name': 'test_net',
+                         'id': 'test_net_id'}]}
+        mock_neutron = mock.MagicMock()
+        mock_neutron.list_networks.return_value = mock_networks
+        mock_os_cli = mock.MagicMock()
+        mock_os_cli.neutron.return_value = mock_neutron
+        self.assertEqual('test_net_id',
+                         attr_validator.validate_fixed_network(mock_os_cli,
+                                                               'test_net'))
+        self.assertTrue(mock_neutron.list_networks.called)
+
+    def test_validate_fixed_network_with_multiple_valid_network(self):
+        mock_networks = {
+            'networks': [{'name': 'test_net',
+                          'id': 'test_net_id1'},
+                         {'name': 'test_net',
+                          'id': 'test_net_id2'}],
+        }
+        mock_neutron = mock.MagicMock()
+        mock_neutron.list_networks.return_value = mock_networks
+        mock_os_cli = mock.MagicMock()
+        mock_os_cli.neutron.return_value = mock_neutron
+        self.assertRaises(exception.Conflict,
+                          attr_validator.validate_fixed_network,
+                          mock_os_cli, 'test_net')
+
+    def test_validate_fixed_network_with_invalid_network(self):
+        mock_networks = {'networks': [{'name': 'test_net_not_equal',
+                         'id': 'test_net_id_not_equal'}]}
+        mock_neutron = mock.MagicMock()
+        mock_neutron.list_networks.return_value = mock_networks
+        mock_os_cli = mock.MagicMock()
+        mock_os_cli.neutron.return_value = mock_neutron
+        self.assertRaises(exception.FixedNetworkNotFound,
+                          attr_validator.validate_fixed_network,
+                          mock_os_cli, 'test_net')
+
     def test_validate_keypair_with_no_keypair(self):
         mock_keypair = mock.MagicMock()
         mock_keypair.id = None