+ /* For now, ovs-ofctl only enables OpenFlow 1.0 by default. This is
+ * because ovs-ofctl implements command such as "add-flow" as raw OpenFlow
+ * requests, but those requests have subtly different semantics in
+ * different OpenFlow versions. For example:
+ *
+ * - In OpenFlow 1.0, a "mod-flow" operation that does not find any
+ * existing flow to modify adds a new flow.
+ *
+ * - In OpenFlow 1.1, a "mod-flow" operation that does not find any
+ * existing flow to modify adds a new flow, but only if the mod-flow
+ * did not match on the flow cookie.
+ *
+ * - In OpenFlow 1.2 and a later, a "mod-flow" operation never adds a
+ * new flow.
+ */
+ set_allowed_ofp_versions("OpenFlow10");
+