diff --git a/utils/os_client.py b/utils/os_client.py
index 03462dc..9b128c5 100644
--- a/utils/os_client.py
+++ b/utils/os_client.py
@@ -408,6 +408,10 @@
                                  "Must be an integer at 'custom_mtu' in "
                                  "global_config.yaml.\n{}".format(mtu, e))
         net = self.os_clients.network.create_network(net_body)['network']
+        # WA for TF because the network object does not have 'mtu' field by
+        # default, so this blocked running tests at TF envs with default MTU
+        if 'mtu' not in net:
+            net['mtu'] = None
         logger.info("Created internal network {}".format(net_name))
         return net
 
@@ -465,3 +469,26 @@
             msg = "Could not delete a Floating IP, UUID {}. Error: {}" \
                   "".format(floatingip_id, e)
             logger.info(msg)
+
+    def is_cloud_tf(self):
+        # Detect the TF cloud by assuming it does not have any neutron
+        # agents (404 in response)
+        try:
+            self.os_clients.network.list_agents()
+        except neutron_common.exceptions.NotFound:
+            logger.info("MOS TF cloud is detected.")
+            return True
+        return False
+
+    def update_network_port_with_custom_mtu(self, vm_uuid, custom_mtu):
+        port_uuid = self.os_clients.network.list_ports(
+            device_id=vm_uuid).get("ports")[0]["id"]
+        body = {"port": {"extra_dhcp_opts": [
+            {"opt_name": "interface-mtu", "opt_value": str(custom_mtu)}]}}
+        try:
+            self.os_clients.network.update_port(port_uuid, body)
+        except Exception as e:
+            raise Exception("Could not set custom MTU by updating the port. "
+                            "See detailed error: {}".format(e))
+        logger.info("The port {} is updated with custom MTU {}."
+                    "".format(port_uuid, custom_mtu))