diff --git a/nova/tests/unit/virt/ironic/test_driver.py b/nova/tests/unit/virt/ironic/test_driver.py
index 736eac24ca90..bf3291833d20 100644
--- a/nova/tests/unit/virt/ironic/test_driver.py
+++ b/nova/tests/unit/virt/ironic/test_driver.py
@@ -2785,8 +2785,8 @@ class IronicDriverGenerateConfigDriveTestCase(test.NoDBTestCase):
                                            node_id=self.node.id,
                                            address='00:00:00:00:00:02',
                                            port_group_id=portgroup.id)
-        self.mock_conn.ports.return_value = [port1, port2]
-        self.mock_conn.port_groups.return_value = [portgroup]
+        self.mock_conn.ports.return_value = iter([port1, port2])
+        self.mock_conn.port_groups.return_value = iter([portgroup])
 
         metadata = self.driver._get_network_metadata(self.node,
                                                      self.network_info)
diff --git a/nova/virt/ironic/driver.py b/nova/virt/ironic/driver.py
index 3af85d3bd049..c99021866962 100644
--- a/nova/virt/ironic/driver.py
+++ b/nova/virt/ironic/driver.py
@@ -1050,10 +1050,10 @@ class IronicDriver(virt_driver.ComputeDriver):
         :param network_info: Instance network information.
         """
         base_metadata = netutils.get_network_metadata(network_info)
-        ports = self.ironic_connection.ports(node=node.id, details=True)
-        port_groups = self.ironic_connection.port_groups(
+        ports = list(self.ironic_connection.ports(node=node.id, details=True))
+        port_groups = list(self.ironic_connection.port_groups(
             node=node.id, details=True,
-        )
+        ))
         vif_id_to_objects = {'ports': {}, 'portgroups': {}}
         for collection, name in ((ports, 'ports'),
                                  (port_groups, 'portgroups')):