Simple strategy to allow address pairs for virtual IP

Change-Id: Ie353b7c7bc95bd7560dd27711582b224016b9815
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/models/yang/vnfd-base.yang b/models/yang/vnfd-base.yang
index 8ee13c0..28a4961 100644
--- a/models/yang/vnfd-base.yang
+++ b/models/yang/vnfd-base.yang
@@ -66,6 +66,17 @@
       type boolean;
       default true;
     }
+
+    leaf port-security-disable-strategy {
+      description "Strategy to disable port security, either Enables the port security for the port.
+                   full                : disable port security in the whole port
+                   allow-address-pairs : allow address pairs for virtual IP (any virtual IP can be configured)";
+      type enumeration {
+        enum full;
+        enum allow-address-pairs;
+      }
+      default full;
+    }
   }
 
   typedef interface-type {