+/**
+ * L3: GRE (i.e. this tunnel is in L3 mode)
+ * TEB: Transparent Ethernet Bridging - the tunnel is in L2 mode
+ * ERSPAN: type 2 - the tunnel is for port mirror SPAN output. Each tunnel is
+ * associated with a session ID and expected to be used for encap
+ * and output of mirrored packet from a L2 network only. There is
+ * no support for receiving ERSPAN packets from a GRE ERSPAN tunnel
+ */
+#define foreach_gre_tunnel_type \
+ _(L3, "L3") \
+ _(TEB, "TEB") \
+ _(ERSPAN, "ERSPAN") \
+
+/**
+ * @brief The GRE tunnel type
+ */
+typedef enum gre_tunnel_type_t_
+{
+#define _(n, s) GRE_TUNNEL_TYPE_##n,
+ foreach_gre_tunnel_type
+#undef _
+} __clib_packed gre_tunnel_type_t;
+
+extern u8 *format_gre_tunnel_type (u8 * s, va_list * args);
+
+