--- openflow-2011-03-18.h	2015-07-23 09:54:16.508479336 -0700
+++ openflow-2011-02-22.h	2015-07-23 09:54:16.512479336 -0700
@@ -211,6 +211,7 @@
     OFPC_IP_REASM       = 1 << 5,  /* Can reassemble IP fragments. */
     OFPC_QUEUE_STATS    = 1 << 6,  /* Queue statistics. */
     OFPC_ARP_MATCH_IP   = 1 << 7   /* Match IP addresses in ARP pkts. */
+    OFPC_PORT_BLOCKED   = 1 << 8,  /* Switch will block looping ports. */
 };
 
 /* Flags to indicate behavior of the physical port.  These flags are