diff --git a/core/net/rpl/Makefile.rpl b/core/net/rpl/Makefile.rpl
index 9a69f9513..7c6b33c98 100644
--- a/core/net/rpl/Makefile.rpl
+++ b/core/net/rpl/Makefile.rpl
@@ -1 +1 @@
-CONTIKI_SOURCEFILES += rpl.c rpl-dag.c rpl-icmp6.c rpl-timers.c rpl-of0.c
+CONTIKI_SOURCEFILES += rpl.c rpl-dag.c rpl-icmp6.c rpl-timers.c rpl-of-etx.c
diff --git a/core/net/rpl/rpl-dag.c b/core/net/rpl/rpl-dag.c
index 3e7c848da..f3c3f63c0 100644
--- a/core/net/rpl/rpl-dag.c
+++ b/core/net/rpl/rpl-dag.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-dag.c,v 1.9 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl-dag.c,v 1.10 2010/05/29 22:23:21 nvt-se Exp $
  */
 /**
  * \file
@@ -57,12 +57,9 @@
 #include "net/uip-debug.h"
 
 /************************************************************************/
-#ifdef RPL_CONF_OBJECTIVE_FUNCTION
-#define RPL_OF                  RPL_CONF_OBJECTIVE_FUNCTION
-#else
-extern rpl_of_t rpl_of0;
-#define RPL_OF                  rpl_of0
-#endif /* RPL_CONF_OBJECTIVE_FUNCTION */
+extern rpl_of_t rpl_of_etx;
+static rpl_of_t *objective_functions[] = {&rpl_of_etx, NULL};
+/************************************************************************/
 
 #ifndef RPL_CONF_MAX_DAG_ENTRIES
 #define RPL_MAX_DAG_ENTRIES     2
@@ -124,7 +121,7 @@ poison_routes(rpl_dag_t *dag, rpl_parent_t *exception)
  }
 }
 /************************************************************************/
-int
+rpl_dag_t *
 rpl_set_root(uip_ipaddr_t *dag_id)
 {
   rpl_dag_t *dag;
@@ -138,7 +135,7 @@ rpl_set_root(uip_ipaddr_t *dag_id)
   dag = rpl_alloc_dag();
   if(dag == NULL) {
     PRINTF("RPL: Failed to allocate a DAG\n");
-    return -1;
+    return NULL;
   }
 
   dag->joined = 1;
@@ -159,7 +156,7 @@ rpl_set_root(uip_ipaddr_t *dag_id)
 
   rpl_reset_dio_timer(dag, 1);
 
-  return 0;
+  return dag;
 }
 /************************************************************************/
 int
@@ -359,9 +356,14 @@ rpl_find_dag(unsigned char aucIndex)
 rpl_of_t *
 rpl_find_of(rpl_ocp_t ocp)
 {
-  if(RPL_OF.ocp == ocp) {
-    return &RPL_OF;
+  rpl_of_t *of;
+
+  for(of = objective_functions[0]; of != NULL; of++) {
+    if(of->ocp == ocp) {
+      return of;
+    }
   }
+
   return NULL;
 }
 /************************************************************************/
@@ -438,7 +440,7 @@ join_dag(uip_ipaddr_t *from, rpl_dio_t *dio)
 
   rpl_set_default_route(dag, from);
 
-  if(dio->dst_adv_trigger) {
+  if(dio->dst_adv_supported && dio->dst_adv_trigger) {
     rpl_schedule_dao(dag);
   } else {
     PRINTF("RPL: dst_adv_trigger not set in incoming DIO!\n");
@@ -511,7 +513,7 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
   /* This DIO pertains to a DAG that we are already part of. */
   p = rpl_find_parent(dag, from);
   if(p != NULL) {
-    if(dio->dst_adv_trigger) {
+    if(dio->dst_adv_supported && dio->dst_adv_trigger) {
       rpl_schedule_dao(dag);
     } else {
       PRINTF("RPL: dst_adv_trigger is not set in incoming DIO\n");
@@ -598,7 +600,7 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
        node is in the parent list, we just remove it. */
     if(p != NULL && p->rank < dio->dag_rank) {
       PRINTF("RPL: Parent ");
-      PRINT6ADDR(&n->addr);
+      PRINT6ADDR(&p->addr);
       PRINTF(" has increased in rank from %hu to %hu. Removing it.\n",
              p->rank, dio->dag_rank);
       rpl_remove_parent(dag, p);
diff --git a/core/net/rpl/rpl-icmp6.c b/core/net/rpl/rpl-icmp6.c
index 48c75fdd8..bed435bc1 100644
--- a/core/net/rpl/rpl-icmp6.c
+++ b/core/net/rpl/rpl-icmp6.c
@@ -33,7 +33,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-icmp6.c,v 1.11 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl-icmp6.c,v 1.12 2010/05/29 22:23:21 nvt-se Exp $
  */
 /**
  * \file
@@ -323,8 +323,8 @@ dio_output(rpl_dag_t *dag, uip_ipaddr_t *uc_addr)
   buffer[pos++] = RPL_DIO_SUBOPT_OCP;
   buffer[pos++] = 0;
   buffer[pos++] = 2;
-  buffer[pos++] = 0;
-  buffer[pos++] = 0;
+  buffer[pos++] = dag->of->ocp >> 8;
+  buffer[pos++] = dag->of->ocp & 0xff;
 
   /* alignment here ??? */
 
diff --git a/core/net/rpl/rpl-of-etx.c b/core/net/rpl/rpl-of-etx.c
new file mode 100644
index 000000000..34b5ed7c8
--- /dev/null
+++ b/core/net/rpl/rpl-of-etx.c
@@ -0,0 +1,121 @@
+/**
+ * \addtogroup uip6
+ * @{
+ */
+/*
+ * Copyright (c) 2010, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ * $Id: rpl-of-etx.c,v 1.1 2010/05/29 22:23:21 nvt-se Exp $
+ */
+/**
+ * \file
+ *         An implementation of RPL's objective function 1 (ETX).
+ *
+ * \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>
+ */
+
+#include "net/rpl/rpl.h"
+
+#define DEBUG DEBUG_ANNOTATE
+#include "net/uip-debug.h"
+
+static void parent_state_callback(rpl_parent_t *, int, int);
+static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
+static rpl_rank_t increment_rank(rpl_rank_t, rpl_parent_t *);
+
+rpl_of_t rpl_of_etx = {
+  parent_state_callback,
+  best_parent,
+  increment_rank,
+  1
+};
+
+#define LINK_ETX_MIN			1
+#define LINK_ETX_MAX			10
+#define PATH_ETX_MIN			1
+#define PATH_ETX_MAX			200
+#define PARENT_SWITCH_ETX_THRESHOLD	0.5
+#define INFINITY			255
+
+typedef unsigned char etx_t;
+
+static etx_t min_path_etx = INFINITY;
+
+static void
+parent_state_callback(rpl_parent_t *parent, int known, int etx)
+{
+  rpl_dag_t *dag;
+
+  dag = (rpl_dag_t *)parent->dag;
+
+  if(known) {
+    if(min_path_etx != INFINITY) {
+      dag->rank = min_path_etx + etx;
+      PRINTF("RPL: New path ETX: %u\n", (unsigned)(min_path_etx + etx));
+    }
+  } else {
+    if(RPL_PARENT_COUNT(dag) == 1) {
+      /* Our last parent has disappeared, set the path ETX to infinity. */
+      min_path_etx = INFINITY;
+    }
+  }
+}
+
+static rpl_rank_t
+increment_rank(rpl_rank_t rank, rpl_parent_t *parent)
+{
+  rpl_rank_t new_rank;
+
+  PRINTF("RPL: OF1 increment rank\n");
+
+  if(parent->rank < min_path_etx) {
+    min_path_etx = parent->rank;
+  }
+
+  new_rank = parent->rank + LINK_ETX_MAX;
+
+  if(new_rank < rank) {
+    return INFINITE_RANK;
+  }
+
+  PRINTF("RPL: Path ETX %u\n", (unsigned)new_rank);
+
+  return new_rank;
+}
+
+static rpl_parent_t *
+best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
+{
+  if(p1->rank < p2->rank) {
+    return p1;
+  }
+
+  return p2;
+}
diff --git a/core/net/rpl/rpl-of0.c b/core/net/rpl/rpl-of0.c
index d9ad5e4b9..8a924cd7a 100644
--- a/core/net/rpl/rpl-of0.c
+++ b/core/net/rpl/rpl-of0.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-of0.c,v 1.2 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl-of0.c,v 1.3 2010/05/29 22:23:21 nvt-se Exp $
  */
 /**
  * \file
@@ -50,6 +50,7 @@ static rpl_parent_t *best_parent(rpl_parent_t *, rpl_parent_t *);
 static rpl_rank_t increment_rank(rpl_rank_t, rpl_parent_t *);
 
 rpl_of_t rpl_of0 = {
+  NULL,
   best_parent,
   increment_rank,
   0
@@ -82,7 +83,6 @@ best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
   PRINTF(" (confidence %d, rank %d)\n",
         p2->local_confidence, p2->rank);
 
-  /* TODO: Add other rules. */
   if(p1->local_confidence > p2->local_confidence) {
     return p1;
   } else if(p2->local_confidence > p1->local_confidence) {
diff --git a/core/net/rpl/rpl-timers.c b/core/net/rpl/rpl-timers.c
index 2f6d60b36..d816061f4 100644
--- a/core/net/rpl/rpl-timers.c
+++ b/core/net/rpl/rpl-timers.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-timers.c,v 1.6 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl-timers.c,v 1.7 2010/05/29 22:23:21 nvt-se Exp $
  */
 /**
  * \file
@@ -210,14 +210,13 @@ rpl_schedule_dao(rpl_dag_t *dag)
 
   expiration_time = etimer_expiration_time(&dag->dao_timer.etimer);
 
-  if(!etimer_expired(&dag->dao_timer.etimer) &&
-     (expiration_time - clock_time()) < (DEFAULT_DAO_LATENCY / dag->rank)) {
+  if(!etimer_expired(&dag->dao_timer.etimer)) {
     PRINTF("RPL: DAO timer already scheduled\n");
   } else {
     PRINTF("RPL: Scheduling DAO timer %u ticks in the future (%u %u)\n",
            (unsigned)DEFAULT_DAO_LATENCY / dag->rank,
            (unsigned)DEFAULT_DAO_LATENCY, (unsigned)dag->rank);
-    ctimer_set(&dag->dao_timer, DEFAULT_DAO_LATENCY / dag->rank,
+    ctimer_set(&dag->dao_timer, DEFAULT_DAO_LATENCY,
                handle_dao_timer, dag);
   }
 }
diff --git a/core/net/rpl/rpl.c b/core/net/rpl/rpl.c
index 789759821..6f2136f74 100644
--- a/core/net/rpl/rpl.c
+++ b/core/net/rpl/rpl.c
@@ -32,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl.c,v 1.4 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl.c,v 1.5 2010/05/29 22:23:21 nvt-se Exp $
  */
 /**
  * \file
@@ -59,9 +59,8 @@
 #define RPL_MAX_ROUTE_ENTRIES   RPL_CONF_MAX_ROUTE_ENTRIES
 #endif /* !RPL_CONF_MAX_ROUTE_ENTRIES */
 
-/************************************************************************/
 extern uip_ds6_route_t uip_ds6_routing_table[UIP_DS6_ROUTE_NB];
-
+/************************************************************************/
 void
 rpl_purge_routes(void)
 {
@@ -125,10 +124,25 @@ neighbor_callback(const rimeaddr_t *addr, int known, int etx)
   PRINTF(" is %sknown. ETX = %d\n", known ? "" : "no longer ", etx);
 
   dag = rpl_get_dag(RPL_DEFAULT_INSTANCE);
-  if(dag == NULL || (parent = rpl_find_parent(dag, &ipaddr)) == NULL) {
+  if(dag == NULL) {
     return;
   }
 
+  parent = rpl_find_parent(dag, &ipaddr);
+  if(parent == NULL) {
+    if(!known) {
+      PRINTF("RPL: Deleting routes installed by DAOs received from ");
+      PRINT6ADDR(&ipaddr);
+      PRINTF("\n");
+      uip_ds6_route_rm_by_nexthop(&ipaddr);
+    }
+    return;
+  }
+
+  if(dag->of->parent_state_callback != NULL) {
+    dag->of->parent_state_callback(parent, known, etx);
+  }
+
   if(!known) {
     PRINTF("RPL: Removing parent ");
     PRINT6ADDR(&parent->addr);
@@ -140,6 +154,9 @@ neighbor_callback(const rimeaddr_t *addr, int known, int etx)
       /* Select a new default route. */
       parent = rpl_preferred_parent(dag);
       if(parent != NULL) {
+	PRINTF("RPL: Switching preferred parent to ");
+        PRINT6ADDR(&parent->addr);
+        PRINTF("\n");
         rpl_set_default_route(dag, &parent->addr);
       }
     }
diff --git a/core/net/rpl/rpl.h b/core/net/rpl/rpl.h
index b01871259..0d04d12ac 100644
--- a/core/net/rpl/rpl.h
+++ b/core/net/rpl/rpl.h
@@ -30,7 +30,7 @@
  *
  * Author: Joakim Eriksson, Nicolas Tsiftes
  *
- * $Id: rpl.h,v 1.4 2010/05/25 21:58:54 nvt-se Exp $
+ * $Id: rpl.h,v 1.5 2010/05/29 22:23:21 nvt-se Exp $
  */
 
 #ifndef RPL_H
@@ -85,7 +85,7 @@
 #define RPL_DEFAULT_INSTANCE            0
 #define RPL_ANY_INSTANCE               -1
 
-#define RPL_DEFAULT_OCP                 0
+#define RPL_DEFAULT_OCP                 1
 
 /* TODO: pick these from OCP later? */
 #define DEFAULT_MAX_RANKINC             16
@@ -138,6 +138,7 @@ struct rpl_parent {
 typedef struct rpl_parent rpl_parent_t;
 
 struct rpl_of {
+  void (*parent_state_callback)(rpl_parent_t *, int, int);
   rpl_parent_t *(*best_parent)(rpl_parent_t *, rpl_parent_t *);
   rpl_rank_t (*increment_rank)(rpl_rank_t, rpl_parent_t *);
   rpl_ocp_t ocp;
@@ -231,7 +232,7 @@ void dao_output(rpl_parent_t *, uint32_t lifetime);
 void uip_rpl_input(void);
 
 /* RPL logic functions. */
-int rpl_set_root(uip_ipaddr_t *);
+rpl_dag_t *rpl_set_root(uip_ipaddr_t *);
 int rpl_set_prefix(rpl_dag_t *dag, uip_ipaddr_t *prefix, int len);
 int rpl_repair_dag(rpl_dag_t *dag);
 int rpl_set_default_route(rpl_dag_t *dag, uip_ipaddr_t *from);