diff --git a/openflow_input/bsn_port_generation_id b/openflow_input/bsn_port_generation_id
new file mode 100644
index 0000000..fddf9a3
--- /dev/null
+++ b/openflow_input/bsn_port_generation_id
@@ -0,0 +1,38 @@
+// Copyright 2015, Big Switch Networks, Inc.
+//
+// LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
+// the following special exception:
+//
+// LOXI Exception
+//
+// As a special exception to the terms of the EPL, you may distribute libraries
+// generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
+// that copyright and licensing notices generated by LoxiGen are not altered or removed
+// from the LoxiGen Libraries and the notice provided below is (i) included in
+// the LoxiGen Libraries, if distributed in source code form and (ii) included in any
+// documentation for the LoxiGen Libraries, if distributed in binary form.
+//
+// Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
+//
+// You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
+// a copy of the EPL at:
+//
+// http://www.eclipse.org/legal/epl-v10.html
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// EPL for the specific language governing permissions and limitations
+// under the EPL.
+
+// This generation ID is changed whenever a port goes link-down.
+
+#version 5
+
+struct of_port_desc_prop_bsn_generation_id : of_port_desc_prop_bsn {
+    uint16_t type == 0xffff;
+    uint16_t length;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t exp_type == 1;
+    uint64_t generation_id;
+};
diff --git a/openflow_input/standard-1.4 b/openflow_input/standard-1.4
index edcc781..18388bd 100644
--- a/openflow_input/standard-1.4
+++ b/openflow_input/standard-1.4
@@ -880,7 +880,7 @@
     uint16_t type == 0xffff;
     uint16_t length;
     uint32_t experimenter == ?;
-    uint32_t exp_type;
+    //uint32_t exp_type;
 };
 
 struct of_port_desc {