diff --git a/neutron/privileged/agent/linux/ip_lib.py b/neutron/privileged/agent/linux/ip_lib.py
index fcf48899337..800cf35bf40 100644
--- a/neutron/privileged/agent/linux/ip_lib.py
+++ b/neutron/privileged/agent/linux/ip_lib.py
@@ -241,11 +241,11 @@ def _translate_ip_device_exception(e, device=None, namespace=None):
 
 
 def get_link_id(device, namespace):
-    try:
-        with get_iproute(namespace) as ip:
-            return ip.link_lookup(ifname=device)[0]
-    except IndexError:
+    with get_iproute(namespace) as ip:
+        link_id = ip.link_lookup(ifname=device)
+    if not link_id or len(link_id) < 1:
         raise NetworkInterfaceNotFound(device=device, namespace=namespace)
+    return link_id[0]
 
 
 def _run_iproute_link(command, device, namespace=None, **kwargs):
diff --git a/neutron/tests/unit/privileged/agent/linux/test_ip_lib.py b/neutron/tests/unit/privileged/agent/linux/test_ip_lib.py
index 2efb168051c..0531a5d31b9 100644
--- a/neutron/tests/unit/privileged/agent/linux/test_ip_lib.py
+++ b/neutron/tests/unit/privileged/agent/linux/test_ip_lib.py
@@ -47,11 +47,24 @@ class IpLibTestCase(base.BaseTestCase):
     def test_run_iproute_link_interface_not_exists(self):
         with mock.patch.object(pyroute2, "IPRoute") as iproute_mock:
             ip_mock = iproute_mock()
-            ip_mock.__enter__().link_lookup.return_value = []
-            self.assertRaises(
-                priv_lib.NetworkInterfaceNotFound,
-                priv_lib._run_iproute_link,
-                "test_cmd", "eth0", None, test_param="test_value")
+            ret_values = [
+                [],    # No interface found.
+                None,  # Unexpected output but also handled.
+            ]
+            for ret_val in ret_values:
+                ip_mock.__enter__().link_lookup.return_value = ret_val
+                self.assertRaises(
+                    priv_lib.NetworkInterfaceNotFound,
+                    priv_lib._run_iproute_link,
+                    "test_cmd", "eth0", None, test_param="test_value")
+
+    @mock.patch.object(priv_lib, 'get_iproute')
+    def test_get_link_id(self, mock_iproute):
+        mock_ip = mock.Mock()
+        mock_ip.link_lookup.return_value = ['interface_id']
+        mock_iproute.return_value.__enter__.return_value = mock_ip
+        self.assertEqual('interface_id',
+                         priv_lib.get_link_id('device', 'namespace'))
 
     def test_run_iproute_link_interface_removed_during_call(self):
         with mock.patch.object(pyroute2, "IPRoute") as iproute_mock: