diff --git a/kolla/common/config.py b/kolla/common/config.py
index 64affd5f49..07136d896f 100755
--- a/kolla/common/config.py
+++ b/kolla/common/config.py
@@ -174,7 +174,7 @@ _CLI_OPTS = [
                 help='Show all available images (filtering supported)'),
     cfg.StrOpt('namespace', short='n', default='kolla',
                help='The Docker namespace name'),
-    cfg.StrOpt('network_mode', default=None,
+    cfg.StrOpt('network_mode', default='host',
                help='The network mode for Docker build. Example: host'),
     cfg.BoolOpt('cache', default=True,
                 help='Use the Docker cache when building'),
diff --git a/kolla/tests/test_build.py b/kolla/tests/test_build.py
index 3e9dd06341..422dfcd73a 100644
--- a/kolla/tests/test_build.py
+++ b/kolla/tests/test_build.py
@@ -166,8 +166,8 @@ class TasksTest(base.TestCase):
 
         mock_client().build.assert_called_once_with(
             path=self.image.path, tag=self.image.canonical_name, decode=True,
-            network_mode=None, nocache=False, rm=True, pull=True, forcerm=True,
-            buildargs=None)
+            network_mode='host', nocache=False, rm=True, pull=True,
+            forcerm=True, buildargs=None)
 
         self.assertTrue(builder.success)
 
@@ -176,14 +176,14 @@ class TasksTest(base.TestCase):
     def test_build_image_with_network_mode(self, mock_client):
         self.dc = mock_client
         push_queue = mock.Mock()
-        self.conf.set_override('network_mode', 'host')
+        self.conf.set_override('network_mode', 'bridge')
 
         builder = build.BuildTask(self.conf, self.image, push_queue)
         builder.run()
 
         mock_client().build.assert_called_once_with(
             path=self.image.path, tag=self.image.canonical_name, decode=True,
-            network_mode='host', nocache=False, rm=True, pull=True,
+            network_mode='bridge', nocache=False, rm=True, pull=True,
             forcerm=True, buildargs=None)
 
         self.assertTrue(builder.success)
@@ -203,8 +203,8 @@ class TasksTest(base.TestCase):
 
         mock_client().build.assert_called_once_with(
             path=self.image.path, tag=self.image.canonical_name, decode=True,
-            network_mode=None, nocache=False, rm=True, pull=True, forcerm=True,
-            buildargs=build_args)
+            network_mode='host', nocache=False, rm=True, pull=True,
+            forcerm=True, buildargs=build_args)
 
         self.assertTrue(builder.success)
 
@@ -222,8 +222,8 @@ class TasksTest(base.TestCase):
 
         mock_client().build.assert_called_once_with(
             path=self.image.path, tag=self.image.canonical_name, decode=True,
-            network_mode=None, nocache=False, rm=True, pull=True, forcerm=True,
-            buildargs=build_args)
+            network_mode='host', nocache=False, rm=True, pull=True,
+            forcerm=True, buildargs=build_args)
 
         self.assertTrue(builder.success)
 
@@ -243,8 +243,8 @@ class TasksTest(base.TestCase):
 
         mock_client().build.assert_called_once_with(
             path=self.image.path, tag=self.image.canonical_name, decode=True,
-            network_mode=None, nocache=False, rm=True, pull=True, forcerm=True,
-            buildargs=build_args)
+            network_mode='host', nocache=False, rm=True, pull=True,
+            forcerm=True, buildargs=build_args)
 
         self.assertTrue(builder.success)
 
diff --git a/releasenotes/notes/network-mode-host-2aca256e2a1fbf68.yaml b/releasenotes/notes/network-mode-host-2aca256e2a1fbf68.yaml
new file mode 100644
index 0000000000..2183791dce
--- /dev/null
+++ b/releasenotes/notes/network-mode-host-2aca256e2a1fbf68.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Changed default of ``network_mode`` to ``host`` since Kolla-Ansible
+    ``bootstrap-servers`` is deploying Docker without a bridge by default
+    since `Wallaby <https://review.opendev.org/c/openstack/kolla-ansible/+/751795>`__