No overlapping sub-nets on any interface in the same table/VRF (VPP-943)

DBGvpp# set int ip addr loop0 10.10.10.10/24
DBGvpp# set int ip addr loop0 10.10.10.11/24
set interface ip address: failed to add 10.10.10.11/24 which conflicts with 10.10.10.10/24 for interface loop0

Change-Id: Iba63ffafbd36b6146ce86adb78139da9d55b40ba
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/test/test_classifier.py b/test/test_classifier.py
index 1753fef..1e29aec 100644
--- a/test/test_classifier.py
+++ b/test/test_classifier.py
@@ -60,6 +60,10 @@
 
     def tearDown(self):
         """Run standard test teardown and acl related log."""
+        for intf in self.interfaces:
+            intf.unconfig_ip4()
+            intf.admin_down()
+
         super(TestClassifier, self).tearDown()
         if not self.vpp_dead:
             self.logger.info(self.vapi.cli("show classify table verbose"))