+#ifndef IPPROTO_MOBILITY_OLD
+/*
+ * The current Protocol Numbers list says that the IP protocol number for
+ * mobility headers is 135; it cites draft-ietf-mobileip-ipv6-24, but
+ * that draft doesn't actually give a number.
+ *
+ * It appears that 62 used to be used, even though that's assigned to
+ * a protocol called CFTP; however, the only reference for CFTP is a
+ * Network Message from BBN back in 1982, so, for now, we support 62,
+ * aas well as 135, as a protocol number for mobility headers.
+ */
+#define IPPROTO_MOBILITY_OLD 62