+ *
+ *
+ * ->port_destruct()
+ * =================
+ *
+ * ->port_destruct() takes a 'del' parameter. If the provider implements
+ * the datapath itself (e.g. dpif-netdev, it can ignore 'del'. On the
+ * other hand, if the provider is an interface to an external datapath
+ * (e.g. to a kernel module that implement the datapath) then 'del' should
+ * influence destruction behavior in the following way:
+ *
+ * - If 'del' is true, it should remove the port from the underlying
+ * implementation. This is the common case.
+ *
+ * - If 'del' is false, it should leave the port in the underlying
+ * implementation. This is used when Open vSwitch is performing a
+ * graceful shutdown and ensures that, across Open vSwitch restarts,
+ * the underlying ports are not removed and recreated. That makes an
+ * important difference for, e.g., "internal" ports that have
+ * configured IP addresses; without this distinction, the IP address
+ * and other configured state for the port is lost.