diff --git a/config_tempest/services/network.py b/config_tempest/services/network.py
index 4cb74f47..2be8a04f 100644
--- a/config_tempest/services/network.py
+++ b/config_tempest/services/network.py
@@ -65,20 +65,29 @@ class NetworkService(VersionedService):
                              ''.format(self._public_network_id))
 
     def _discover_network(self):
-        LOG.info("No network supplied, trying auto discover for network")
+        LOG.info("No network supplied, trying auto discover for an external "
+                 "network while prioritizing the one called public, if not "
+                 "found, the network discovered last will be used.")
         network_list = self.client.list_networks()
+
         for network in network_list['networks']:
             if network['router:external'] and network['subnets']:
-                LOG.info("Found network, using: %s", network['id'])
+                if network['status'] != 'ACTIVE':
+                    continue
                 self._public_network_id = network['id']
                 self._public_network_name = network['name']
-                break
-
+                # usually the external network we use is called 'public'
+                if network['name'] == 'public':
+                    # we found a network called public, end the loop
+                    break
         # Couldn't find an existing external network
-        else:
+        if not self._public_network_name:
             LOG.error("No external networks found. "
                       "Please note that any test that relies on external "
                       "connectivity would most likely fail.")
+            return
+        LOG.info("Setting %s as the public network for tempest",
+                 self._public_network_id)
 
     @staticmethod
     def get_service_type():
diff --git a/config_tempest/tests/services/test_network.py b/config_tempest/tests/services/test_network.py
index f21af89e..d2d85bc6 100644
--- a/config_tempest/tests/services/test_network.py
+++ b/config_tempest/tests/services/test_network.py
@@ -35,6 +35,18 @@ class TestNetworkService(BaseServiceTest):
             'label': 'my_fake_label',
             'name': 'tempest-network',
             'admin_state_up': True,
+        }, {
+            'provider:physical_network': None,
+            'id': 'c034f7f8-b860-4ffd',
+            'router:external': True,
+            'availability_zone_hints': [],
+            'availability_zones': [],
+            'ipv4_address_scope': None,
+            'status': 'ACTIVE',
+            'subnets': ['fake_subnet 2'],
+            'label': 'public_fake_label',
+            'name': 'public',
+            'admin_state_up': True,
         }]
     }
 
@@ -70,15 +82,18 @@ class TestNetworkService(BaseServiceTest):
         return_mock = mock.Mock(return_value=self.FAKE_NETWORK_LIST)
         self.Service.client.list_networks = return_mock
         self.Service._discover_network()
-        self.assertEqual(self.Service._public_network_id, '1ea533d7-4c65-4f25')
-        self.assertEqual(self.Service._public_network_name, 'tempest-network')
+        self.assertEqual(self.Service._public_network_id,
+                         'c034f7f8-b860-4ffd')
+        self.assertEqual(self.Service._public_network_name, 'public')
 
     @mock.patch('config_tempest.services.network.LOG')
     def test_create_network_auto_discover_not_found(self, mock_logging):
-        # delete subnets => network will not be found
+        # delete subnets, set DOWN status => networks will not be found
         self.FAKE_NETWORK_LIST['networks'][0]['subnets'] = []
+        self.FAKE_NETWORK_LIST['networks'][1]['status'] = 'DOWN'
         return_mock = mock.Mock(return_value=self.FAKE_NETWORK_LIST)
         self.Service.client.list_networks = return_mock
+        self.Service._public_network_name = None
         self.Service._discover_network()
         # check if LOG.error was called
         self.assertTrue(mock_logging.error.called)
diff --git a/releasenotes/notes/prioritize-external-network-named-public-fe84c304e536177e.yaml b/releasenotes/notes/prioritize-external-network-named-public-fe84c304e536177e.yaml
new file mode 100644
index 00000000..34ca899d
--- /dev/null
+++ b/releasenotes/notes/prioritize-external-network-named-public-fe84c304e536177e.yaml
@@ -0,0 +1,9 @@
+---
+fixes:
+  - |
+    python-tempestconf will prioritize the external network named public when
+    auto-discovering an external network for tempest. The public network is
+    the network we end up using in most of the cases. This will help avoid
+    potential conflicts with other available external networks that are not
+    meant to be used by tempest. If no external network with name public is
+    found, the network discovered last will be used.