diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 237d9d94d3b9..fdf8d4e7756f 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -6470,10 +6470,11 @@ class ComputeManager(manager.Manager):
                 utils.get_image_from_system_metadata(
                     instance.system_metadata))
 
-        self.network_api.setup_instance_network_on_host(context, instance,
-                                                        self.host)
-        network_info = self.network_api.get_instance_nw_info(context, instance)
         try:
+            self.network_api.setup_instance_network_on_host(context, instance,
+                                                            self.host)
+            network_info = self.network_api.get_instance_nw_info(
+                context, instance)
             with self.rt.instance_claim(context, instance, node, allocations,
                                         limits):
                 self.driver.spawn(context, instance, image_meta,
diff --git a/nova/tests/functional/regressions/test_bug_1862633.py b/nova/tests/functional/regressions/test_bug_1862633.py
index 9990734b3614..5d3826a39110 100644
--- a/nova/tests/functional/regressions/test_bug_1862633.py
+++ b/nova/tests/functional/regressions/test_bug_1862633.py
@@ -82,11 +82,6 @@ class UnshelveNeutronErrorTest(
                  'OS-EXT-STS:task_state': None})
 
         # As the instance went back to offloaded state we expect no allocation
-        # allocations = self.placement_api.get(
-        #     '/allocations/%s' % server['id']).body['allocations']
-        # self.assertEqual(0, len(allocations))
-        #
-        # but the allocation is leaked this is bug 1862633
         allocations = self.placement_api.get(
             '/allocations/%s' % server['id']).body['allocations']
-        self.assertEqual(1, len(allocations))
+        self.assertEqual(0, len(allocations))