diff --git a/core/net/rpl/rpl-of-etx.c b/core/net/rpl/rpl-of-etx.c
index 466d86ca6..05a521c83 100644
--- a/core/net/rpl/rpl-of-etx.c
+++ b/core/net/rpl/rpl-of-etx.c
@@ -66,11 +66,6 @@ rpl_of_t rpl_of_etx = {
   1
 };
 
-#define NI_ETX_TO_RPL_ETX(etx)						\
-	((etx) * (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
-#define RPL_ETX_TO_NI_ETX(etx)					\
-	((etx) / (RPL_DAG_MC_ETX_DIVISOR / NEIGHBOR_INFO_ETX_DIVISOR))
-
 /* Reject parents that have a higher link metric than the following. */
 #define MAX_LINK_METRIC			10
 
@@ -90,8 +85,11 @@ calculate_path_metric(rpl_parent_t *p)
 {
   if(p == NULL || (p->mc.obj.etx == 0 && p->rank > ROOT_RANK(p->dag->instance))) {
     return MAX_PATH_COST * RPL_DAG_MC_ETX_DIVISOR;
+  } else {
+    long etx = p->link_metric;
+    etx = (etx * RPL_DAG_MC_ETX_DIVISOR) / NEIGHBOR_INFO_ETX_DIVISOR;
+    return p->mc.obj.etx + (uint16_t) etx;
   }
-  return p->mc.obj.etx + NI_ETX_TO_RPL_ETX(p->link_metric);
 }
 
 static void
@@ -116,7 +114,8 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
     }
     rank_increase = NEIGHBOR_INFO_FIX2ETX(INITIAL_LINK_METRIC) * DEFAULT_MIN_HOPRANKINC;
   } else {
-    rank_increase = NEIGHBOR_INFO_FIX2ETX(p->link_metric) * p->dag->instance->min_hoprankinc;
+    /* multiply first, then scale down to avoid truncation effects */
+    rank_increase = NEIGHBOR_INFO_FIX2ETX(p->link_metric * p->dag->instance->min_hoprankinc);
     if(base_rank == 0) {
       base_rank = p->rank;
     }
diff --git a/core/net/rpl/rpl-private.h b/core/net/rpl/rpl-private.h
index a4fb43b83..94eaec0d8 100644
--- a/core/net/rpl/rpl-private.h
+++ b/core/net/rpl/rpl-private.h
@@ -129,7 +129,7 @@
 #else
 #define DEFAULT_MIN_HOPRANKINC          RPL_CONF_MIN_HOPRANKINC
 #endif
-#define DEFAULT_MAX_RANKINC             (3 * DEFAULT_MIN_HOPRANKINC)
+#define DEFAULT_MAX_RANKINC             (7 * DEFAULT_MIN_HOPRANKINC)
 
 #define DAG_RANK(fixpt_rank, instance)	((fixpt_rank) / (instance)->min_hoprankinc)
 
diff --git a/examples/ipv6/native-border-router/project-conf.h b/examples/ipv6/native-border-router/project-conf.h
index 6258b4eca..90576783a 100644
--- a/examples/ipv6/native-border-router/project-conf.h
+++ b/examples/ipv6/native-border-router/project-conf.h
@@ -37,7 +37,7 @@
 #define QUEUEBUF_CONF_NUM         4
 
 #undef UIP_CONF_BUFFER_SIZE
-#define UIP_CONF_BUFFER_SIZE    140
+#define UIP_CONF_BUFFER_SIZE    1280
 
 #undef UIP_CONF_RECEIVE_WINDOW
 #define UIP_CONF_RECEIVE_WINDOW  60