diff --git a/core/net/rpl/rpl-ext-header.c b/core/net/rpl/rpl-ext-header.c
index 96c709f71..2bd0cb77c 100644
--- a/core/net/rpl/rpl-ext-header.c
+++ b/core/net/rpl/rpl-ext-header.c
@@ -75,12 +75,6 @@ rpl_verify_header(int uip_ext_opt_offset)
     return 1;
   }
 
-  if(UIP_EXT_HDR_OPT_RPL_BUF->flags & RPL_HDR_OPT_FWD_ERR) {
-    PRINTF("RPL: Forward error!\n");
-    /* We should try to repair it, not implemented for the moment */
-    return 2;
-  }
-
   instance = rpl_get_instance(UIP_EXT_HDR_OPT_RPL_BUF->instance);
   if(instance == NULL) {
     PRINTF("RPL: Unknown instance: %u\n",
@@ -88,6 +82,31 @@ rpl_verify_header(int uip_ext_opt_offset)
     return 1;
   }
 
+  if(UIP_EXT_HDR_OPT_RPL_BUF->flags & RPL_HDR_OPT_FWD_ERR) {
+    PRINTF("RPL: Forward error!\n");
+    /* We should try to repair it by removing the neighbor that caused
+       the packet to be forwareded in the first place. We drop any
+       routes that go through the neighbor that sent the packet to
+       us. */
+    uip_ds6_route_t *route;
+    route = uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr);
+    if(route != NULL) {
+      uip_ds6_route_rm(route);
+
+      /* If we are the root and just needed to remove a DAO route,
+         chances are that the network needs to be repaired. The
+         rpl_repair_root() function will cause a global repair if we
+         happen to be the root node of the dag. */
+      PRINTF("RPL: initiate global repair\n");
+      rpl_repair_root(instance->instance_id);
+    }
+
+    /* Remove the forwarding error flag and return 0 to let the packet
+       be forwarded again. */
+    UIP_EXT_HDR_OPT_RPL_BUF->flags &= ~RPL_HDR_OPT_FWD_ERR;
+    return 0;
+  }
+
   if(!instance->current_dag->joined) {
     PRINTF("RPL: No DAG in the instance\n");
     return 1;
@@ -191,18 +210,29 @@ rpl_update_header_empty(void)
     PRINTF("RPL: Updating RPL option\n");
     UIP_EXT_HDR_OPT_RPL_BUF->senderrank = instance->current_dag->rank;
 
-
-    /* Set the down extension flag correctly as described in Section
-       11.2 of RFC6550. If the packet progresses along a DAO route,
-       the down flag should be set. */
-
-    if(uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr) == NULL) {
-      /* No route was found, so this packet will go towards the RPL
-	 root. If so, we should not set the down flag. */
-      UIP_EXT_HDR_OPT_RPL_BUF->flags &= ~RPL_HDR_OPT_DOWN;
+    /* Check the direction of the down flag, as per Section 11.2.2.3,
+       which states that if a packet is going down it should in
+       general not go back up again. If this happens, a
+       RPL_HDR_OPT_FWD_ERR should be flagged. */
+    if((UIP_EXT_HDR_OPT_RPL_BUF->flags & RPL_HDR_OPT_DOWN)) {
+      if(uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr) == NULL) {
+        UIP_EXT_HDR_OPT_RPL_BUF->flags |= RPL_HDR_OPT_FWD_ERR;
+        PRINTF("RPL forwarding error\n");
+      }
     } else {
-      /* A DAO route was found so we set the down flag. */
-      UIP_EXT_HDR_OPT_RPL_BUF->flags |= RPL_HDR_OPT_DOWN;
+      /* Set the down extension flag correctly as described in Section
+         11.2 of RFC6550. If the packet progresses along a DAO route,
+         the down flag should be set. */
+      if(uip_ds6_route_lookup(&UIP_IP_BUF->destipaddr) == NULL) {
+        /* No route was found, so this packet will go towards the RPL
+           root. If so, we should not set the down flag. */
+        UIP_EXT_HDR_OPT_RPL_BUF->flags &= ~RPL_HDR_OPT_DOWN;
+        PRINTF("RPL option going up\n");
+      } else {
+        /* A DAO route was found so we set the down flag. */
+        UIP_EXT_HDR_OPT_RPL_BUF->flags |= RPL_HDR_OPT_DOWN;
+        PRINTF("RPL option going down\n");
+      }
     }
 
     uip_ext_len = last_uip_ext_len;