diff --git a/src/core/ipv6/ethip6.c b/src/core/ipv6/ethip6.c
index 35d424e3..32d0edf6 100644
--- a/src/core/ipv6/ethip6.c
+++ b/src/core/ipv6/ethip6.c
@@ -62,7 +62,9 @@
  * For IPv6 multicast, corresponding Ethernet addresses
  * are selected and the packet is transmitted on the link.
  *
- * For unicast addresses, ...
+ * For unicast addresses, ask the ND6 module what to do. It will either let us
+ * send the the packet right away, or queue the packet for later itself, unless
+ * an error occurs.
  *
  * @todo anycast addresses
  *
@@ -71,14 +73,14 @@
  * @param ip6addr The IP address of the packet destination.
  *
  * @return
- * - ERR_RTE No route to destination (no gateway to external networks),
- * or the return type of either nd6_queue_packet() or ethernet_output().
+ * - ERR_OK or the return value of nd6_packet_send_check.
  */
 err_t
 ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
 {
   struct eth_addr dest;
-  s8_t i;
+  const u8_t *hwaddr;
+  err_t result;
 
   /* multicast destination IP address? */
   if (ip6_addr_ismulticast(ip6addr)) {
@@ -96,31 +98,21 @@ ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
 
   /* We have a unicast destination IP address */
   /* @todo anycast? */
-  /* Get next hop record. */
-  i = nd6_get_next_hop_entry(ip6addr, netif);
-  if (i < 0) {
-    /* failed to get a next hop neighbor record. */
-    return i;
+
+  /* Ask ND6 what to do with the packet. */
+  result = nd6_packet_send_check(netif, q, ip6addr, &hwaddr);
+  if (result != ERR_OK) {
+    return result;
   }
 
-  /* Now that we have a destination record, send or queue the packet. */
-  if (neighbor_cache[i].state == ND6_STALE) {
-    /* Switch to delay state. */
-    neighbor_cache[i].state = ND6_DELAY;
-    neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME / ND6_TMR_INTERVAL;
-  }
-  /* @todo should we send or queue if PROBE? send for now, to let unicast NS pass. */
-  if ((neighbor_cache[i].state == ND6_REACHABLE) ||
-      (neighbor_cache[i].state == ND6_DELAY) ||
-      (neighbor_cache[i].state == ND6_PROBE)) {
-
-    /* Send out. */
-    SMEMCPY(dest.addr, neighbor_cache[i].lladdr, 6);
-    return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
+  /* If no hardware address is returned, nd6 has queued the packet for later. */
+  if (hwaddr == NULL) {
+    return ERR_OK;
   }
 
-  /* We should queue packet on this interface. */
-  return nd6_queue_packet(i, q);
+  /* Send out the packet using the returned hardware address. */
+  SMEMCPY(dest.addr, hwaddr, 6);
+  return ethernet_output(netif, q, (struct eth_addr*)(netif->hwaddr), &dest, ETHTYPE_IPV6);
 }
 
 #endif /* LWIP_IPV6 && LWIP_ETHERNET */
diff --git a/src/core/ipv6/nd6.c b/src/core/ipv6/nd6.c
index fb4e7339..8bb337f1 100644
--- a/src/core/ipv6/nd6.c
+++ b/src/core/ipv6/nd6.c
@@ -98,6 +98,8 @@ static s8_t nd6_get_router(const ip6_addr_t *router_addr, struct netif *netif);
 static s8_t nd6_new_router(const ip6_addr_t *router_addr, struct netif *netif);
 static s8_t nd6_get_onlink_prefix(ip6_addr_t *prefix, struct netif *netif);
 static s8_t nd6_new_onlink_prefix(ip6_addr_t *prefix, struct netif *netif);
+static s8_t nd6_get_next_hop_entry(const ip6_addr_t *ip6addr, struct netif *netif);
+static err_t nd6_queue_packet(s8_t neighbor_index, struct pbuf *q);
 
 #define ND6_SEND_FLAG_MULTICAST_DEST 0x01
 #define ND6_SEND_FLAG_ALLNODES_DEST 0x02
@@ -1562,7 +1564,7 @@ nd6_new_onlink_prefix(ip6_addr_t *prefix, struct netif *netif)
  *         suitable next hop was found, ERR_MEM if no cache entry
  *         could be created
  */
-s8_t
+static s8_t
 nd6_get_next_hop_entry(const ip6_addr_t *ip6addr, struct netif *netif)
 {
 #ifdef LWIP_HOOK_ND6_GET_GW
@@ -1684,7 +1686,7 @@ nd6_get_next_hop_entry(const ip6_addr_t *ip6addr, struct netif *netif)
  * @param q packet to be queued
  * @return ERR_OK if succeeded, ERR_MEM if out of memory
  */
-err_t
+static err_t
 nd6_queue_packet(s8_t neighbor_index, struct pbuf *q)
 {
   err_t result = ERR_MEM;
@@ -1861,6 +1863,60 @@ nd6_send_q(s8_t i)
 #endif /* LWIP_ND6_QUEUEING */
 }
 
+/**
+ * A packet is to be transmitted to a specific IPv6 destination on a specific
+ * interface. Check if we can find the hardware address of the next hop to use
+ * for the packet. If so, give the hardware address to the caller, which should
+ * use it to send the packet right away. Otherwise, enqueue the packet for
+ * later transmission while looking up the hardware address, if possible.
+ *
+ * As such, this function returns one of three different possible results:
+ *
+ * - ERR_OK with a non-NULL 'hwaddrp': the caller should send the packet now.
+ * - ERR_OK with a NULL 'hwaddrp': the packet has been enqueued for later.
+ * - not ERR_OK: something went wrong; forward the error upward in the stack.
+ *
+ * @param netif The lwIP network interface on which the IP packet will be sent.
+ * @param q The pbuf(s) containing the IP packet to be sent.
+ * @param ip6addr The destination IPv6 address of the packet.
+ * @param hwaddrp On success, filled with a pointer to a HW address or NULL.
+ * @return
+ * - ERR_OK on success, ERR_RTE if no route was found for the packet,
+ * or ERR_MEM if low memory conditions prohibit sending the packet at all.
+ */
+err_t
+nd6_packet_send_check(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr, const u8_t **hwaddrp)
+{
+  s8_t i;
+
+  /* Get next hop record. */
+  i = nd6_get_next_hop_entry(ip6addr, netif);
+  if (i < 0) {
+    /* failed to get a next hop neighbor record. */
+    return i;
+  }
+
+  /* Now that we have a destination record, send or queue the packet. */
+  if (neighbor_cache[i].state == ND6_STALE) {
+    /* Switch to delay state. */
+    neighbor_cache[i].state = ND6_DELAY;
+    neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME / ND6_TMR_INTERVAL;
+  }
+  /* @todo should we send or queue if PROBE? send for now, to let unicast NS pass. */
+  if ((neighbor_cache[i].state == ND6_REACHABLE) ||
+      (neighbor_cache[i].state == ND6_DELAY) ||
+      (neighbor_cache[i].state == ND6_PROBE)) {
+
+    /* Tell the caller to send out the packet now. */
+    *hwaddrp = neighbor_cache[i].lladdr;
+    return ERR_OK;
+  }
+
+  /* We should queue packet on this interface. */
+  *hwaddrp = NULL;
+  return nd6_queue_packet(i, q);
+}
+
 
 /**
  * Get the Path MTU for a destination.
diff --git a/src/include/lwip/nd6.h b/src/include/lwip/nd6.h
index 1d4b2f26..97df6b0b 100644
--- a/src/include/lwip/nd6.h
+++ b/src/include/lwip/nd6.h
@@ -142,10 +142,9 @@ extern u32_t retrans_timer;
 void nd6_tmr(void);
 void nd6_input(struct pbuf *p, struct netif *inp);
 void nd6_clear_destination_cache(void);
-s8_t nd6_get_next_hop_entry(const ip6_addr_t *ip6addr, struct netif *netif);
 struct netif *nd6_find_route(const ip6_addr_t *ip6addr);
+err_t nd6_packet_send_check(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr, const u8_t **hwaddrp);
 u16_t nd6_get_destination_mtu(const ip6_addr_t *ip6addr, struct netif *netif);
-err_t nd6_queue_packet(s8_t neighbor_index, struct pbuf *p);
 #if LWIP_ND6_TCP_REACHABILITY_HINTS
 void nd6_reachability_hint(const ip6_addr_t *ip6addr);
 #endif /* LWIP_ND6_TCP_REACHABILITY_HINTS */
diff --git a/src/netif/lowpan6.c b/src/netif/lowpan6.c
index eca9a453..36c041ad 100644
--- a/src/netif/lowpan6.c
+++ b/src/netif/lowpan6.c
@@ -616,7 +616,8 @@ lowpan4_output(struct netif *netif, struct pbuf *q, const ip4_addr_t *ipaddr)
 err_t
 lowpan6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
 {
-  s8_t i;
+  err_t result;
+  const u8_t *hwaddr;
   struct ieee_802154_addr src, dest;
 #if LWIP_6LOWPAN_INFER_SHORT_ADDRESS
   ip6_addr_t ip6_src;
@@ -663,35 +664,23 @@ lowpan6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
   }
 #endif /* LWIP_6LOWPAN_INFER_SHORT_ADDRESS */
 
-
-  /* Get next hop record. */
-  i = nd6_get_next_hop_entry(ip6addr, netif);
-  if (i < 0) {
+  /* Ask ND6 what to do with the packet. */
+  result = nd6_packet_send_check(netif, q, ip6addr, &hwaddr);
+  if (result != ERR_OK) {
     MIB2_STATS_NETIF_INC(netif, ifoutdiscards);
-    /* failed to get a next hop neighbor record. */
-    return ERR_MEM;
+    return result;
   }
 
-  /* Now that we have a destination record, send or queue the packet. */
-  if (neighbor_cache[i].state == ND6_STALE) {
-    /* Switch to delay state. */
-    neighbor_cache[i].state = ND6_DELAY;
-    neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
-  }
-  /* @todo should we send or queue if PROBE? send for now, to let unicast NS pass. */
-  if ((neighbor_cache[i].state == ND6_REACHABLE) ||
-      (neighbor_cache[i].state == ND6_DELAY) ||
-      (neighbor_cache[i].state == ND6_PROBE)) {
-
-    /* Send out. */
-    dest.addr_len = netif->hwaddr_len;
-    SMEMCPY(dest.addr, neighbor_cache[i].lladdr, netif->hwaddr_len);
-    MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
-    return lowpan6_frag(netif, q, &src, &dest);
+  /* If no hardware address is returned, nd6 has queued the packet for later. */
+  if (hwaddr == NULL) {
+    return ERR_OK;
   }
 
-  /* We should queue packet on this interface. */
-  return nd6_queue_packet(i, q);
+  /* Send out the packet using the returned hardware address. */
+  dest.addr_len = netif->hwaddr_len;
+  SMEMCPY(dest.addr, hwaddr, netif->hwaddr_len);
+  MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
+  return lowpan6_frag(netif, q, &src, &dest);
 }
 
 static struct pbuf *