diff --git a/zebra/irdp.h b/zebra/irdp.h
new file mode 100644
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--- /dev/null
+++ b/zebra/irdp.h
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+/* ICMP Router Discovery Messages
+ * Copyright (C) 1997, 2000 Kunihiro Ishiguro
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.  
+ */
+
+/* ICMP Messages */
+#ifndef ICMP_ROUTERADVERT
+#define ICMP_ROUTERADVERT 9
+#endif /* ICMP_ROUTERADVERT */
+
+#ifndef ICMP_ROUTERSOLICIT
+#define ICMP_ROUTERSOLICIT 10
+#endif /* ICMP_ROUTERSOLICT */
+
+/* Multicast groups */
+#ifndef INADDR_ALLHOSTS_GROUP
+#define INADDR_ALLHOSTS_GROUP 0xe0000001    /* 224.0.0.1 */
+#endif /* INADDR_ALLHOSTS_GROUP */
+
+#ifndef INADDR_ALLRTRS_GROUP
+#define INADDR_ALLRTRS_GROUP  0xe0000002    /* 224.0.0.2 */
+#endif /* INADDR_ALLRTRS_GROUP */
+
+/* Comments comes from RFC1256 ICMP Router Discovery Messages. */
+struct irdp_router_interface 
+{
+  /* The IP destination address to be used for multicast Router
+     Advertisements sent from the interface.  The only permissible
+     values are the all-systems multicast address, 224.0.0.1, or the
+     limited-broadcast address, 255.255.255.255.  (The all-systems
+     address is preferred wherever possible, i.e., on any link where
+     all listening hosts support IP multicast.)
+
+     Default: 224.0.0.1 if the router supports IP multicast on the
+     interface, else 255.255.255.255 */
+
+  struct in_addr AdvertisementAddress;
+
+  /* The maximum time allowed between sending multicast Router
+     Advertisements from the interface, in seconds.  Must be no less
+     than 4 seconds and no greater than 1800 seconds.
+
+     Default: 600 seconds */
+
+  unsigned long MaxAdvertisementInterval;
+
+  /* The minimum time allowed between sending unsolicited multicast
+     Router Advertisements from the interface, in seconds.  Must be no
+     less than 3 seconds and no greater than MaxAdvertisementInterval.
+
+     Default: 0.75 * MaxAdvertisementInterval */
+
+  unsigned long MinAdvertisementInterval;
+
+
+  /* The value to be placed in the Lifetime field of Router
+     Advertisements sent from the interface, in seconds.  Must be no
+     less than MaxAdvertisementInterval and no greater than 9000
+     seconds.
+
+     Default: 3 * MaxAdvertisementInterval */
+
+  unsigned long AdvertisementLifetime;
+
+  /* A flag indicating whether or not the address is to be advertised.
+
+     Default: TRUE */
+
+  int Advertise;
+
+
+  /* The preferability of the address as a default router address,
+     relative to other router addresses on the same subnet.  A 32-bit,
+     signed, twos-complement integer, with higher values meaning more
+     preferable.  The minimum value (hex 80000000) is used to indicate
+     that the address, even though it may be advertised, is not to be
+     used by neighboring hosts as a default router address.
+
+     Default: 0 */
+
+  unsigned long PreferenceLevel;
+};
+
+struct irdp_host_interface 
+{
+  /* A flag indicating whether or not the host is to perform ICMP router
+     discovery on the interface. */
+  int PerformRouerDiscovery;
+  
+  /* The IP destination address to be used for sending Router
+     Solicitations from the interface.  The only permissible values
+     are the all-routers multicast address, 224.0.0.2, or the
+     limited-broadcast address, 255.255.255.255.  (The all-routers
+     address is preferred wherever possible, i.e., on any link where
+     all advertising routers support IP multicast.)  */
+  unsigned long SolicitationAddress;
+};
+
+
+/* Route preference structure */
+struct irdp 
+{
+  struct in_addr prefix;
+  long pref;		/* preference level */
+  long timer;			/* lifetime timer */
+
+  struct irdp *next;		/* doubly linked list */
+  struct irdp *prev;		/* doubly linked list */
+};
+
+/* Default irdp packet interval */
+#define IRDP_DEFAULT_INTERVAL 300
+
+/* Router constants from RFC1256 */
+#define MAX_INITIAL_ADVERT_INTERVAL 16
+#define MAX_INITIAL_ADVERTISEMENTS   3
+#define MAX_RESPONSE_DELAY           2
+
+/* Host constants from RFC1256 */
+#define MAX_SOLICITATION_DELAY       1
+#define SOLICITATION_INTERVAL        3
+#define MAX_SOLICITATIONS            3
+
+enum
+{
+  IRDP_NONE,
+  IRDP_ROUTER,
+  IRDP_HOST,
+};
+
+/* default is host mode */
+extern int irdp_mode;