diff --git a/net/sixlowpan/sixlowpan_hc06.c b/net/sixlowpan/sixlowpan_hc06.c
index 0af4aed8b8..b3b25982e5 100644
--- a/net/sixlowpan/sixlowpan_hc06.c
+++ b/net/sixlowpan/sixlowpan_hc06.c
@@ -766,11 +766,11 @@ void sixlowpan_compresshdr_hc06(FAR struct ieee802154_driver_s *ieee,
                                 SIXLOWPAN_IPHC_SAM_BIT);
     }
 
-  /* No address context found for this address */
+  /* No address context found for the source address */
 
   else if (net_is_addr_linklocal(ipv6->srcipaddr) &&
-           ipv6->destipaddr[1] == 0 &&  ipv6->destipaddr[2] == 0 &&
-           ipv6->destipaddr[3] == 0)
+           ipv6->srcipaddr[1] == 0 &&  ipv6->srcipaddr[2] == 0 &&
+           ipv6->srcipaddr[3] == 0)
     {
       iphc1   |= compress_laddr(ipv6->srcipaddr,
                                 &ieee->i_dev.d_mac.ieee802154,
@@ -778,7 +778,7 @@ void sixlowpan_compresshdr_hc06(FAR struct ieee802154_driver_s *ieee,
     }
   else
     {
-      /* Send the full address ipaddr:  SAC = 0, SAM = 00 */
+      /* Send the full source address ipaddr:  SAC = 0, SAM = 00 */
 
       ninfo("Uncompressable srcipaddr=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
             ipv6->srcipaddr[0], ipv6->srcipaddr[1], ipv6->srcipaddr[2],
diff --git a/net/sixlowpan/sixlowpan_udpsend.c b/net/sixlowpan/sixlowpan_udpsend.c
index f4324d1694..6e636bc68b 100644
--- a/net/sixlowpan/sixlowpan_udpsend.c
+++ b/net/sixlowpan/sixlowpan_udpsend.c
@@ -223,7 +223,7 @@ ssize_t psock_6lowpan_udp_sendto(FAR struct socket *psock,
   if (dev == NULL)
 #endif
     {
-      nwarn("WARNING: Not routable\n");
+      nwarn("WARNING: Not routable or not IEEE802.15.4 MAC\n");
       return (ssize_t)-ENETUNREACH;
     }
 #endif
@@ -260,6 +260,8 @@ ssize_t psock_6lowpan_udp_sendto(FAR struct socket *psock,
   net_ipv6addr_hdrcopy(ipv6udp.ipv6.destipaddr, to6->sin6_addr.in6_u.u6_addr16);
 #ifdef CONFIG_NETDEV_MULTINIC
   net_ipv6addr_hdrcopy(ipv6udp.ipv6.srcipaddr,  conn->u.ipv6.laddr);
+#else
+  net_ipv6addr_hdrcopy(ipv6udp.ipv6.srcipaddr,  dev->d_ipv6addr);
 #endif
 
   ninfo("IPv6 length: %d\n",
diff --git a/wireless/ieee802154/mac802154_loopback.c b/wireless/ieee802154/mac802154_loopback.c
index 28c84b117f..8f67e2b3ac 100644
--- a/wireless/ieee802154/mac802154_loopback.c
+++ b/wireless/ieee802154/mac802154_loopback.c
@@ -311,6 +311,10 @@ static int lo_loopback(FAR struct net_driver_s *dev)
   ind.dest.mode = IEEE802154_ADDRMODE_SHORT;
 #endif
 
+  /* Only loopback the local address is the destination and some (arbitrary)
+   * address is the source.
+   */
+
   IEEE802154_PANIDCOPY(ind.src.panid, g_panid);
   IEEE802154_SADDRCOPY(ind.src.saddr, g_src_saddr);
   IEEE802154_EADDRCOPY(ind.src.eaddr, g_src_eaddr);