+/* PPPIOC[GS]MTU are alternatives to SIOC[GS]IFMTU, used under Ultrix */
+#define PPPIOCGMTU _IOR('t', 73, int) /* get interface MTU */
+#define PPPIOCSMTU _IOW('t', 72, int) /* set interface MTU */
+
+/*
+ * These two are interface ioctls so that pppstats can do them on
+ * a socket without having to open the serial device.
+ */