diff --git a/unit_tests/charm_tests/test_tempest.py b/unit_tests/charm_tests/test_tempest.py
index 9c4fc9a..3c4c161 100644
--- a/unit_tests/charm_tests/test_tempest.py
+++ b/unit_tests/charm_tests/test_tempest.py
@@ -42,7 +42,7 @@ class TestTempestSetup(unittest.TestCase):
             'TEST_GATEWAY': 'test',
             'TEST_CIDR_EXT': 'test',
             'TEST_FIP_RANGE': 'test',
-            'TEST_NAMESERVER': 'test',
+            'TEST_NAME_SERVER': 'test',
             'TEST_CIDR_PRIV': 'test',
         }
         tempest_setup.add_environment_var_config(ctxt, ['neutron'])
@@ -55,7 +55,7 @@ class TestTempestSetup(unittest.TestCase):
         ctxt = {}
         get_deployment_context.return_value = {
             'TEST_GATEWAY': 'test',
-            'TEST_NAMESERVER': 'test',
+            'TEST_NAME_SERVER': 'test',
             'TEST_CIDR_PRIV': 'test',
         }
         with self.assertRaises(Exception) as context:
diff --git a/zaza/openstack/charm_tests/tempest/setup.py b/zaza/openstack/charm_tests/tempest/setup.py
index 98ea327..5c85d9c 100644
--- a/zaza/openstack/charm_tests/tempest/setup.py
+++ b/zaza/openstack/charm_tests/tempest/setup.py
@@ -26,10 +26,12 @@ import zaza.openstack.charm_tests.glance.setup as glance_setup
 
 SETUP_ENV_VARS = {
     'neutron': ['TEST_GATEWAY', 'TEST_CIDR_EXT', 'TEST_FIP_RANGE',
-                'TEST_NAMESERVER', 'TEST_CIDR_PRIV'],
+                'TEST_NAME_SERVER', 'TEST_CIDR_PRIV'],
     'swift': ['TEST_SWIFT_IP'],
 }
 
+IGNORABLE_VARS = ['TEST_CIDR_PRIV']
+
 TEMPEST_FLAVOR_NAME = 'm1.tempest'
 TEMPEST_ALT_FLAVOR_NAME = 'm2.tempest'
 TEMPEST_SVC_LIST = ['ceilometer', 'cinder', 'glance', 'heat', 'horizon',
@@ -198,7 +200,8 @@ def add_environment_var_config(ctxt, services):
                 if value:
                     ctxt[var.lower()] = value
                 else:
-                    missing_vars.append(var)
+                    if var not in IGNORABLE_VARS:
+                        missing_vars.append(var)
     if missing_vars:
         raise ValueError(
             ("Environment variables [{}] must all be set to run this"
diff --git a/zaza/openstack/charm_tests/tempest/templates/tempest_v2.j2 b/zaza/openstack/charm_tests/tempest/templates/tempest_v2.j2
index 83a05ca..d4b8810 100644
--- a/zaza/openstack/charm_tests/tempest/templates/tempest_v2.j2
+++ b/zaza/openstack/charm_tests/tempest/templates/tempest_v2.j2
@@ -52,9 +52,11 @@ http_image = http://{{ test_swift_ip }}:80/swift/v1/images/cirros-0.3.4-x86_64-u
 
 {% if 'neutron' in enabled_services %}
 [network]
+{% if test_cidr_priv %}
 project_network_cidr = {{ test_cidr_priv }}
+{% endif %}
 public_network_id = {{ ext_net }}
-dns_servers = {{ test_nameserver }}
+dns_servers = {{ test_name_server }}
 project_networks_reachable = false
 
 [network-feature-enabled]
diff --git a/zaza/openstack/charm_tests/tempest/templates/tempest_v3.j2 b/zaza/openstack/charm_tests/tempest/templates/tempest_v3.j2
index 0ed401a..b441f2d 100644
--- a/zaza/openstack/charm_tests/tempest/templates/tempest_v3.j2
+++ b/zaza/openstack/charm_tests/tempest/templates/tempest_v3.j2
@@ -54,9 +54,11 @@ http_image = http://{{ test_swift_ip }}:80/swift/v1/images/cirros-0.3.4-x86_64-u
 
 {% if 'neutron' in enabled_services %}
 [network]
+{% if test_cidr_priv %}
 project_network_cidr = {{ test_cidr_priv }}
+{% endif %}
 public_network_id = {{ ext_net }}
-dns_servers = {{ test_nameserver }}
+dns_servers = {{ test_name_server }}
 project_networks_reachable = false
 floating_network_name = {{ ext_net }}