diff --git a/core/net/rpl/rpl-dag.c b/core/net/rpl/rpl-dag.c
index e96f5e5d8..8443b176e 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 1.34 2010/10/25 20:03:37 nvt-se Exp $
+ * $Id: rpl-dag.c,v 1.35 2010/10/27 00:46:40 nvt-se Exp $
  */
 /**
  * \file
@@ -108,7 +108,7 @@ remove_parents(rpl_dag_t *dag, rpl_rank_t minimum_rank)
 
   for(p = list_head(dag->parents); p != NULL; p = p2) {
     p2 = p->next;
-    if(DAG_RANK(p->rank, dag) >= minimum_rank) {
+    if(p->rank >= minimum_rank) {
       rpl_remove_parent(dag, p);
     }
   }
@@ -265,6 +265,7 @@ rpl_add_parent(rpl_dag_t *dag, rpl_dio_t *dio, uip_ipaddr_t *addr)
 
   p = memb_alloc(&parent_memb);
   if(p == NULL) {
+    RPL_STAT(rpl_stats.mem_overflows++);
     return NULL;
   }
 
@@ -506,6 +507,7 @@ global_repair(uip_ipaddr_t *from, rpl_dag_t *dag, rpl_dio_t *dio)
   PRINTF("RPL: Participating in a global repair (version=%u, rank=%hu)\n",
          dag->version, dag->rank);
 
+  RPL_STAT(rpl_stats.global_repairs++);
 }
 /************************************************************************/
 int
@@ -521,6 +523,18 @@ rpl_repair_dag(rpl_dag_t *dag)
 }
 /************************************************************************/
 void
+rpl_local_repair(rpl_dag_t *dag)
+{
+  PRINTF("RPL: Starting a local DAG repair\n");
+
+  dag->rank = INFINITE_RANK;
+  remove_parents(dag, 0);
+  rpl_reset_dio_timer(dag, 1);
+
+  RPL_STAT(rpl_stats.local_repairs++);
+}
+/************************************************************************/
+void
 rpl_recalculate_ranks(void)
 {
   rpl_dag_t *dag;
@@ -560,9 +574,8 @@ rpl_process_parent_event(rpl_dag_t *dag, rpl_parent_t *p)
 
   if(rpl_select_parent(dag) == NULL) {
     /* No suitable parent; trigger a local repair. */
-    PRINTF("RPL: No more parents, triggering a local repair\n");
-    dag->rank = INFINITE_RANK;
-    rpl_reset_dio_timer(dag, 1);
+    PRINTF("RPL: No parents found in a DAG\n");
+    rpl_local_repair(dag);
     return 1;
   }
 
@@ -650,7 +663,7 @@ rpl_process_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
   if(p == NULL) {
     if(RPL_PARENT_COUNT(dag) == RPL_MAX_PARENTS) {
       /* Try to make room for a new parent. */
-      remove_parents(dag, DAG_RANK(dio->rank, dag));
+      remove_parents(dag, dio->rank);
     }
 
     /* Add the DIO sender as a candidate parent. */
diff --git a/core/net/rpl/rpl-icmp6.c b/core/net/rpl/rpl-icmp6.c
index 724287e23..19c335163 100644
--- a/core/net/rpl/rpl-icmp6.c
+++ b/core/net/rpl/rpl-icmp6.c
@@ -1,4 +1,3 @@
-
 /**
  * \addtogroup uip6
  * @{
@@ -33,7 +32,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: rpl-icmp6.c,v 1.24 2010/10/25 19:49:12 nvt-se Exp $
+ * $Id: rpl-icmp6.c,v 1.25 2010/10/27 00:46:40 nvt-se Exp $
  */
 /**
  * \file
@@ -238,16 +237,24 @@ dio_input(void)
       len = 2 + buffer[i + 1];
     }
 
+    if(len + i > buffer_length) {
+      PRINTF("RPL: Invalid DIO packet\n");
+      RPL_STAT(rpl_stats.malformed_msgs++);
+      return;
+    }
+
     switch(subopt_type) {
     case RPL_DIO_SUBOPT_DAG_MC:
       if(len < 7) {
         PRINTF("RPL: Invalid DAG MC, len = %d\n", len);
+	RPL_STAT(rpl_stats.malformed_msgs++);
         return;
       }
       break;
     case RPL_DIO_SUBOPT_ROUTE_INFO:
       if(len < 9) {
         PRINTF("RPL: Invalid destination prefix option, len = %d\n", len);
+	RPL_STAT(rpl_stats.malformed_msgs++);
         return;
       }
       /* flags is both preference and flags for now */
@@ -262,6 +269,8 @@ dio_input(void)
                (dio.destination_prefix.length + 7) / 8);
       } else {
         PRINTF("RPL: Invalid route infoprefix option, len = %d\n", len);
+	RPL_STAT(rpl_stats.malformed_msgs++);
+	return;
       }
 
       break;
@@ -280,6 +289,7 @@ dio_input(void)
     case RPL_DIO_SUBOPT_PREFIX_INFO:
       if(len != 32) {
         PRINTF("RPL: DAG Prefix info not ok, len != 32\n");
+	RPL_STAT(rpl_stats.malformed_msgs++);
         return;
       }
       dio.prefix_info.length = buffer[i + 2];
@@ -488,9 +498,9 @@ dao_input(void)
     /* Check if this is a DAO forwarding loop. */
     p = rpl_find_parent(dag, &dao_sender_addr);
     if(p != NULL && p->rank < dag->rank) {
-      printf("RPL: Loop detected when receiving a unicast DAO from a node with a lower rank!\n");
-      dag->rank = INFINITE_RANK;
-      rpl_reset_dio_timer(dag, 1);
+      printf("RPL: Loop detected when receiving a unicast DAO from a node with a lower rank! (%u < %u)\n",
+	DAG_RANK(p->rank, dag), DAG_RANK(dag->rank, dag));
+      rpl_local_repair(dag);
       return;
     }
   }
diff --git a/core/net/rpl/rpl.c b/core/net/rpl/rpl.c
index dede06a29..519bf9b0f 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 1.10 2010/10/22 13:50:13 nvt-se Exp $
+ * $Id: rpl.c,v 1.11 2010/10/27 00:46:40 nvt-se Exp $
  */
 /**
  * \file
@@ -51,6 +51,11 @@
 #include "net/uip-debug.h"
 
 #include <limits.h>
+#include <string.h>
+
+#if RPL_CONF_STATS
+rpl_stats_t rpl_stats;
+#endif
 
 /************************************************************************/
 extern uip_ds6_route_t uip_ds6_routing_table[UIP_DS6_ROUTE_NB];
@@ -204,5 +209,8 @@ rpl_init(void)
 
   rpl_reset_periodic_timer();
   neighbor_info_subscribe(rpl_link_neighbor_callback);
+#if RPL_CONF_STATS
+  memset(&rpl_stats, 0, sizeof(rpl_stats));
+#endif
 }
 /************************************************************************/
diff --git a/core/net/rpl/rpl.h b/core/net/rpl/rpl.h
index 66f8a3b1d..da3350822 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 1.21 2010/10/22 13:13:40 joxe Exp $
+ * $Id: rpl.h,v 1.22 2010/10/27 00:46:40 nvt-se Exp $
  */
 
 #ifndef RPL_H
@@ -241,6 +241,23 @@ struct rpl_dio {
 
 typedef struct rpl_dio rpl_dio_t;
 
+#if RPL_CONF_STATS
+/* Statistics for fault management. */
+struct rpl_stats {
+  uint16_t mem_overflows;
+  uint16_t local_repairs;
+  uint16_t global_repairs;
+  uint16_t malformed_msgs;
+};
+typedef struct rpl_stats rpl_stats_t;
+
+extern rpl_stats_t rpl_stats;
+
+#define RPL_STAT(code)	(code) 
+#else
+#define RPL_STAT(code)
+#endif /* RPL_CONF_STATS */
+
 /* Directed Acyclic Graph */
 struct rpl_dag {
   /* DAG configuration */
@@ -297,6 +314,7 @@ void uip_rpl_input(void);
 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);
+void rpl_local_repair(rpl_dag_t *dag);
 int rpl_set_default_route(rpl_dag_t *dag, uip_ipaddr_t *from);
 void rpl_process_dio(uip_ipaddr_t *, rpl_dio_t *);
 int rpl_process_parent_event(rpl_dag_t *, rpl_parent_t *);