diff --git a/drivers/mtd/w25.c b/drivers/mtd/w25.c
index 35177965171..70f7ff82599 100644
--- a/drivers/mtd/w25.c
+++ b/drivers/mtd/w25.c
@@ -879,7 +879,7 @@ static void w25_cacheflush(struct w25_dev_s *priv)
       /* Write entire erase block to FLASH */
 
       w25_pagewrite(priv, priv->sector, (off_t)priv->esectno << W25_SECTOR_SHIFT,
-                      W25_SECTOR_SIZE);
+                    W25_SECTOR_SIZE);
 
       /* The case is no long dirty and the FLASH is no longer erased */
 
@@ -905,8 +905,8 @@ static FAR uint8_t *w25_cacheread(struct w25_dev_s *priv, off_t sector)
    * shift to the right by 3 to get the sector number in 4096 increments.
    */
 
-  shift    = W25_SECTOR_SHIFT - W25_SECTOR512_SHIFT;
-  esectno  = sector >> shift;
+  shift   = W25_SECTOR_SHIFT - W25_SECTOR512_SHIFT;
+  esectno = sector >> shift;
   finfo("sector: %ld esectno: %d shift=%d\n", sector, esectno, shift);
 
   /* Check if the requested erase block is already in the cache */
diff --git a/include/nuttx/net/ip.h b/include/nuttx/net/ip.h
index bae0091b8c1..88a95dae993 100644
--- a/include/nuttx/net/ip.h
+++ b/include/nuttx/net/ip.h
@@ -563,7 +563,8 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_loopback
  *
  * Description:
- *   Is Ithe Pv6 address a the loopback address?
+ *   Is Ithe Pv6 address a the loopback address?  See RFC 4291 (replaces
+ *   3513).
  *
  ****************************************************************************/
 
@@ -575,7 +576,8 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_unspecified
  *
  * Description:
- *   Is Ithe IPv6 address the unspecified address?
+ *   Is Ithe IPv6 address the unspecified address?  See RFC 4291 (replaces
+ *   3513).
  *
  ****************************************************************************/
 
@@ -587,7 +589,7 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_mcast
  *
  * Description:
- *   Is address a multicast address?  See RFC 3513:
+ *   Is address a multicast address?  See RFC 4291 (replaces 3513):
  *
  *   An IPv6 multicast address is an identifier for a group of interfaces
  *   (typically on different nodes).  An interface may belong to any number
@@ -598,8 +600,9 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  *     |11111111|flgs|scop|                  group ID                   |
  *     +--------+----+----+---------------------------------------------+
  *
- *   binary 11111111 at the start of the address identifies the address as
- *   being a multicast address.
+ *   Bits 120-127: Prefix == 0b11111111
+ *   Bits 116-119: Flags (3 defined)
+ *   Bits 112-115: Scope
  *
  ****************************************************************************/
 
@@ -609,7 +612,8 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_linklocal_allnodes_mcast
  *
  * Description:
- *   Is IPv6 address a the link local all-nodes multicast address?
+ *   Is IPv6 address a the link local all-nodes multicast address?  See RFC
+ *   2375
  *
  ****************************************************************************/
 
@@ -621,7 +625,8 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_linklocal_allrouters_mcast
  *
  * Description:
- *   Is IPv6 address a the link local all-routers multicast address?
+ *   Is IPv6 address a the link local all-routers multicast address?  See RFC
+ *   2375
  *
  ****************************************************************************/
 
@@ -633,12 +638,24 @@ bool net_ipv6addr_maskcmp(const net_ipv6addr_t addr1,
  * Name: net_is_addr_linklocal
  *
  * Description:
- *   Checks whether the address a is link local.
+ *   Checks whether the address 'a' is a link local unicast address.  See
+ *   RFC 4291 (replaces 3513).
  *
  ****************************************************************************/
 
 #define net_is_addr_linklocal(a) ((a)[0] == HTONS(0xfe80))
 
+/****************************************************************************
+ * Name: net_is_addr_sitelocal
+ *
+ * Description:
+ *   Checks whether the address 'a' is a site local unicast address.  See
+ *   RFC 4291 (replaces 3513).
+ *
+ ****************************************************************************/
+
+#define net_is_addr_sitelocal(a) ((a)[0] == HTONS(0xfec0))
+
 #undef EXTERN
 #ifdef __cplusplus
 }
diff --git a/net/devif/ipv6_input.c b/net/devif/ipv6_input.c
index 328ce73c188..d905c416258 100644
--- a/net/devif/ipv6_input.c
+++ b/net/devif/ipv6_input.c
@@ -324,12 +324,14 @@ int ipv6_input(FAR struct net_driver_s *dev)
       return udp_ipv6_input(dev);
     }
 
-  /* In other cases, the device must be assigned a non-zero IP address. */
+  /* In other cases, the device must be assigned a non-zero IP address
+   * (the all zero address is the "unspecified" address.
+   */
 
   else
 #endif
 #ifdef CONFIG_NET_ICMPv6
-  if (net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_allzeroaddr))
+  if (net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_unspecaddr))
     {
       /* If we are configured to use ping IP address configuration and
        * hasn't been assigned an IP address yet, we accept all ICMP
diff --git a/net/icmpv6/icmpv6_autoconfig.c b/net/icmpv6/icmpv6_autoconfig.c
index 0b8939e2540..b5074b77e42 100644
--- a/net/icmpv6/icmpv6_autoconfig.c
+++ b/net/icmpv6/icmpv6_autoconfig.c
@@ -516,7 +516,7 @@ int icmpv6_autoconfig(FAR struct net_driver_s *dev)
 
       /* No off-link communications; No router address. */
 
-      net_ipv6addr_copy(dev->d_ipv6draddr, g_ipv6_allzeroaddr);
+      net_ipv6addr_copy(dev->d_ipv6draddr, g_ipv6_unspecaddr);
 
       /* Set a netmask for the local link address */
 
diff --git a/net/icmpv6/icmpv6_neighbor.c b/net/icmpv6/icmpv6_neighbor.c
index db05e46b32a..f73d702e88d 100644
--- a/net/icmpv6/icmpv6_neighbor.c
+++ b/net/icmpv6/icmpv6_neighbor.c
@@ -212,8 +212,8 @@ int icmpv6_neighbor(const net_ipv6addr_t ipaddr)
    *   addresses=0xff (ff00::/8.)
    */
 
-  if (net_ipv6addr_cmp(ipaddr, g_ipv6_allzeroaddr) ||
-      (ipaddr[0] & NTOHS(0xff00)) == NTOHS(0xff00))
+  if (net_ipv6addr_cmp(ipaddr, g_ipv6_unspecaddr) ||
+      net_is_addr_mcast(ipaddr))
     {
       /* We don't need to send the Neighbor Solicitation */
 
@@ -222,7 +222,7 @@ int icmpv6_neighbor(const net_ipv6addr_t ipaddr)
 
   /* Get the device that can route this request */
 
-  dev = netdev_findby_ipv6addr(g_ipv6_allzeroaddr, ipaddr);
+  dev = netdev_findby_ipv6addr(g_ipv6_unspecaddr, ipaddr);
   if (!dev)
     {
       nerr("ERROR: Unreachable: %08lx\n", (unsigned long)ipaddr);
diff --git a/net/icmpv6/icmpv6_sendto.c b/net/icmpv6/icmpv6_sendto.c
index e179e3d434b..8e5ad48837b 100644
--- a/net/icmpv6/icmpv6_sendto.c
+++ b/net/icmpv6/icmpv6_sendto.c
@@ -388,7 +388,8 @@ ssize_t icmpv6_sendto(FAR struct socket *psock, FAR const void *buf, size_t len,
 
   /* Get the device that will be used to route this ICMPv6 ECHO request */
 
-  dev = netdev_findby_ipv6addr(g_ipv6_allzeroaddr, inaddr->sin6_addr.s6_addr16);
+  dev = netdev_findby_ipv6addr(g_ipv6_unspecaddr,
+                               inaddr->sin6_addr.s6_addr16);
   if (dev == NULL)
     {
       nerr("ERROR: Not reachable\n");
diff --git a/net/inet/inet.h b/net/inet/inet.h
index d48e3f39bd3..9e81bda98f8 100644
--- a/net/inet/inet.h
+++ b/net/inet/inet.h
@@ -91,7 +91,7 @@ EXTERN uint16_t g_ipid;
 /* Well-known IPv6 addresses */
 
 #ifdef CONFIG_NET_IPv6
-EXTERN const net_ipv6addr_t g_ipv6_allzeroaddr; /* An address of all zeroes */
+EXTERN const net_ipv6addr_t g_ipv6_unspecaddr;  /* An address of all zeroes */
 EXTERN const net_ipv6addr_t g_ipv6_allnodes;    /* All link local nodes */
 #if defined(CONFIG_NET_ICMPv6_AUTOCONF) || defined(CONFIG_NET_ICMPv6_ROUTER)
 EXTERN const net_ipv6addr_t g_ipv6_allrouters;  /* All link local routers */
diff --git a/net/inet/inet_globals.c b/net/inet/inet_globals.c
index 23b1d65c092..d6f4087be48 100644
--- a/net/inet/inet_globals.c
+++ b/net/inet/inet_globals.c
@@ -61,12 +61,14 @@ uint16_t g_ipid;
 
 #ifdef CONFIG_NET_IPv6
 
-const net_ipv6addr_t g_ipv6_allzeroaddr = /* An address of all zeroes */
+/* Unspecified address (all zero).  See RFC 4291 (replaces 3513) */
+
+const net_ipv6addr_t g_ipv6_unspecaddr =  /* An address of all zeroes */
 {
   0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000
 };
 
-/* IPv6 Multi-cast IP addresses */
+/* IPv6 Multi-cast IP addresses.  See RFC 2375 */
 
 const net_ipv6addr_t g_ipv6_allnodes =    /* All link local nodes */
 {
diff --git a/net/inet/ipv6_getsockname.c b/net/inet/ipv6_getsockname.c
index 1606f568377..8de7c5b7d38 100644
--- a/net/inet/ipv6_getsockname.c
+++ b/net/inet/ipv6_getsockname.c
@@ -132,12 +132,12 @@ int ipv6_getsockname(FAR struct socket *psock, FAR struct sockaddr *addr,
         return -EOPNOTSUPP;
     }
 
-  /* Check if bound to local INADDR6_ANY */
+  /* Check if bound to the IPv6 unspecified address */
 
-  if (net_ipv6addr_cmp(lipaddr, g_ipv6_allzeroaddr))
+  if (net_ipv6addr_cmp(lipaddr, g_ipv6_unspecaddr))
     {
       outaddr->sin6_family = AF_INET6;
-      memcpy(outaddr->sin6_addr.in6_u.u6_addr8, g_ipv6_allzeroaddr, 16);
+      memcpy(outaddr->sin6_addr.in6_u.u6_addr8, g_ipv6_unspecaddr, 16);
       *addrlen = sizeof(struct sockaddr_in6);
 
       return OK;
@@ -146,17 +146,16 @@ int ipv6_getsockname(FAR struct socket *psock, FAR struct sockaddr *addr,
   net_lock();
 
   /* Find the device matching the IPv6 address in the connection structure.
-   * NOTE: listening sockets have no ripaddr.  Work around is to use the
+   * NOTE:  listening sockets have no ripaddr.  Work around is to use the
    * lipaddr when ripaddr is not available.
    */
 
-  if (net_ipv6addr_cmp(ripaddr, g_ipv6_allzeroaddr))
+  if (net_ipv6addr_cmp(ripaddr, g_ipv6_unspecaddr))
     {
       ripaddr = lipaddr;
     }
 
   dev = netdev_findby_ipv6addr(*lipaddr, *ripaddr);
-
   if (!dev)
     {
       net_unlock();
diff --git a/net/neighbor/neighbor_ethernet_out.c b/net/neighbor/neighbor_ethernet_out.c
index 4da54e42fc2..60aad3e750e 100644
--- a/net/neighbor/neighbor_ethernet_out.c
+++ b/net/neighbor/neighbor_ethernet_out.c
@@ -43,6 +43,7 @@
 #include <debug.h>
 
 #include <nuttx/net/arp.h>
+#include <nuttx/net/ip.h>
 #include <nuttx/net/netdev.h>
 
 #include "route/route.h"
@@ -159,12 +160,7 @@ void neighbor_out(FAR struct net_driver_s *dev)
    * packet with an Neighbor Solicitation Request for the IPv6 address.
    */
 
-  /* First check if destination is a IPv6 multicast address.  IPv6
-   * multicast addresses in IPv6 have the prefix ff00::/8
-   *
-   *   Bits 120-127: Prefix
-   *   Bits 116-119: Flags (1, 2, or 3 defined)
-   *   Bits 112-115: Scope
+  /* First check if destination is a IPv6 multicast address.
    *
    * REVISIT: Need to revisit IPv6 broadcast support.  Broadcast
    * IP addresses are not used with IPv6; multicast is used instead.
@@ -172,7 +168,7 @@ void neighbor_out(FAR struct net_driver_s *dev)
    * broadcast Ethernet address?
    */
 
-  if ((ip->destipaddr[0] & HTONS(0xff00)) == HTONS(0xff00))
+  if (net_is_addr_mcast(ip->destipaddr))
     {
       memcpy(eth->dest, g_broadcast_ethaddr.ether_addr_octet,
              ETHER_ADDR_LEN);
diff --git a/net/netdev/netdev_findbyaddr.c b/net/netdev/netdev_findbyaddr.c
index 32e634792a1..5328d04db7d 100644
--- a/net/netdev/netdev_findbyaddr.c
+++ b/net/netdev/netdev_findbyaddr.c
@@ -304,9 +304,11 @@ FAR struct net_driver_s *netdev_findby_ipv6addr(const net_ipv6addr_t lipaddr,
 
   if (net_is_addr_mcast(ripaddr))
     {
-      /* Yes.. Check the local, bound address.  Is it INADDR_ANY? */
+      /* Yes.. Check the local, bound address.  Is it the IPv6 unspecified
+       * address?
+       */
 
-      if (net_ipv6addr_cmp(lipaddr, g_ipv6_allzeroaddr))
+      if (net_ipv6addr_cmp(lipaddr, g_ipv6_unspecaddr))
         {
           /* Yes.. In this case, I think we are supposed to send the
            * broadcast packet out ALL locally available networks.  I am not
diff --git a/net/netdev/netdev_ifconf.c b/net/netdev/netdev_ifconf.c
index f3f850c48f1..469974256c5 100644
--- a/net/netdev/netdev_ifconf.c
+++ b/net/netdev/netdev_ifconf.c
@@ -183,7 +183,7 @@ static int ifconf_ipv6_callback(FAR struct net_driver_s *dev, FAR void *arg)
    * state.
    */
 
-  if (!net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_allzeroaddr) &&
+  if (!net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_unspecaddr) &&
       (dev->d_flags & IFF_UP) != 0)
     {
       /* Check if we would exceed the buffer space provided by the caller.
diff --git a/net/sixlowpan/sixlowpan_tcpsend.c b/net/sixlowpan/sixlowpan_tcpsend.c
index 45d1b52b171..66ce10eb357 100644
--- a/net/sixlowpan/sixlowpan_tcpsend.c
+++ b/net/sixlowpan/sixlowpan_tcpsend.c
@@ -220,7 +220,7 @@ static int sixlowpan_tcp_header(FAR struct tcp_conn_s *conn,
   /* Copy the source and destination addresses */
 
   net_ipv6addr_hdrcopy(ipv6tcp->ipv6.destipaddr, conn->u.ipv6.raddr);
-  if (!net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr))
+  if (!net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
     {
       net_ipv6addr_hdrcopy(ipv6tcp->ipv6.srcipaddr, conn->u.ipv6.laddr);
     }
diff --git a/net/sixlowpan/sixlowpan_udpsend.c b/net/sixlowpan/sixlowpan_udpsend.c
index 6f99f31b7c6..1b7a591b058 100644
--- a/net/sixlowpan/sixlowpan_udpsend.c
+++ b/net/sixlowpan/sixlowpan_udpsend.c
@@ -255,7 +255,7 @@ ssize_t psock_6lowpan_udp_sendto(FAR struct socket *psock,
   /* Copy the source and destination addresses */
 
   net_ipv6addr_hdrcopy(ipv6udp.ipv6.destipaddr, to6->sin6_addr.in6_u.u6_addr16);
-  if (!net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr))
+  if (!net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
     {
       net_ipv6addr_hdrcopy(ipv6udp.ipv6.srcipaddr, conn->u.ipv6.laddr);
     }
diff --git a/net/sixlowpan/sixlowpan_utils.c b/net/sixlowpan/sixlowpan_utils.c
index 35394134181..8cf4481badc 100644
--- a/net/sixlowpan/sixlowpan_utils.c
+++ b/net/sixlowpan/sixlowpan_utils.c
@@ -274,7 +274,7 @@ int sixlowpan_destaddrfromip(FAR struct radio_driver_s *radio,
 
    /* Check for a multicast address */
 
-   if (net_is_addr_mcast(ipaddr[0]))
+   if (net_is_addr_mcast(ipaddr))
      {
         DEBUGASSERT(radio->r_properties != NULL);
         ret = radio->r_properties(radio, &properties);
diff --git a/net/tcp/tcp_conn.c b/net/tcp/tcp_conn.c
index 9ce5d60e2d6..94b36813061 100644
--- a/net/tcp/tcp_conn.c
+++ b/net/tcp/tcp_conn.c
@@ -179,13 +179,13 @@ tcp_ipv6_listener(const net_ipv6addr_t ipaddr, uint16_t portno)
       if (conn->tcpstateflags != TCP_CLOSED && conn->lport == portno)
         {
           /* If there are multiple interface devices, then the local IP
-           * address of the connection must also match.  INADDR_ANY is a
-           * special case:  There can only be instance of a port number
-           * with INADDR_ANY.
+           * address of the connection must also match.  The IPv6
+           * unspecified address is a special case:  There can only be
+           * one instance of a port number with the unspecified address.
            */
 
           if (net_ipv6addr_cmp(conn->u.ipv6.laddr, ipaddr) ||
-              net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr))
+              net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
             {
               /* The port number is in use, return the connection */
 
@@ -408,8 +408,8 @@ static inline FAR struct tcp_conn_s *
        * - The remote port number is checked if the connection is bound
        *   to a remote port.
        * - Insist that the destination IP matches the bound address. If
-       *   a socket is bound to INADDRY_ANY, then it should receive all
-       *   packets directed to the port.
+       *   a socket is bound to the IPv6 unspecified address, then it
+       *   should receive all packets directed to the port.
        * - Finally, if the connection is bound to a remote IP address,
        *   the source IP address of the packet is checked.
        *
@@ -420,7 +420,7 @@ static inline FAR struct tcp_conn_s *
       if (conn->tcpstateflags != TCP_CLOSED &&
           tcp->destport == conn->lport &&
           tcp->srcport  == conn->rport &&
-          (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr) ||
+          (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr) ||
            net_ipv6addr_cmp(*destipaddr, conn->u.ipv6.laddr)) &&
           net_ipv6addr_cmp(*srcipaddr, conn->u.ipv6.raddr))
         {
@@ -563,7 +563,7 @@ static inline int tcp_ipv6_bind(FAR struct tcp_conn_s *conn,
       /* Back out the local address setting */
 
       conn->lport = 0;
-      net_ipv6addr_copy(conn->u.ipv6.laddr, g_ipv6_allzeroaddr);
+      net_ipv6addr_copy(conn->u.ipv6.laddr, g_ipv6_unspecaddr);
       return ret;
     }
 
diff --git a/net/tcp/tcp_finddev.c b/net/tcp/tcp_finddev.c
index 411e5c9c3d0..feccc8400bb 100644
--- a/net/tcp/tcp_finddev.c
+++ b/net/tcp/tcp_finddev.c
@@ -131,12 +131,12 @@ static int tcp_find_ipv6_device(FAR struct tcp_conn_s *conn,
     }
 
   /* Return success without using device notification if the locally bound
-   * address is IN6ADDR_ANY.  In this case, there may be multiple devices
-   * that can provide data so the exceptional events from any particular
-   * device are not important.
+   * address is the IPv6 unspecified address.  In this case, there may be
+   * multiple devices* that can provide data so the exceptional events from
+   * any particular device are not important.
    */
 
-  if (net_ipv6addr_cmp(addr, g_ipv6_allzeroaddr))
+  if (net_ipv6addr_cmp(addr, g_ipv6_unspecaddr))
     {
       return OK;
     }
diff --git a/net/udp/udp_conn.c b/net/udp/udp_conn.c
index ac45e1173bc..bd8304a5325 100644
--- a/net/udp/udp_conn.c
+++ b/net/udp/udp_conn.c
@@ -177,7 +177,7 @@ static FAR struct udp_conn_s *udp_find_conn(uint8_t domain,
         {
           if (conn->lport == portno &&
               (net_ipv6addr_cmp(conn->u.ipv6.laddr, ipaddr->ipv6.laddr) ||
-               net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr)))
+               net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr)))
             {
               return conn;
             }
@@ -463,10 +463,11 @@ static inline FAR struct udp_conn_s *
           /* Check if the local port accepts any address on this port or
            * that there is an exact match between the destipaddr and the
            * bound local address.  This catches the case of the all nodes
-           * multicast when the socket is bound to INADDR6_ANY.
+           * multicast when the socket is bound to the IPv6 unspecified
+           * address.
            */
 
-          (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr) ||
+          (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr) ||
            net_ipv6addr_hdrcmp(ip->destipaddr, conn->u.ipv6.laddr))))
         {
           /* Check if the socket is connection mode.  In this case, only
@@ -489,7 +490,7 @@ static inline FAR struct udp_conn_s *
                * address, then accept the packet.
                */
 
-                  (net_ipv6addr_cmp(conn->u.ipv6.raddr, g_ipv6_allzeroaddr) ||
+                  (net_ipv6addr_cmp(conn->u.ipv6.raddr, g_ipv6_unspecaddr) ||
 #ifdef CONFIG_NET_BROADCAST
                    net_ipv6addr_hdrcmp(ip->destipaddr, g_ipv6_allnodes) ||
 #endif
@@ -887,7 +888,7 @@ int udp_connect(FAR struct udp_conn_s *conn, FAR const struct sockaddr *addr)
       else
 #endif
         {
-          net_ipv6addr_copy(conn->u.ipv6.raddr, g_ipv6_allzeroaddr);
+          net_ipv6addr_copy(conn->u.ipv6.raddr, g_ipv6_unspecaddr);
         }
 #endif /* CONFIG_NET_IPv6 */
     }
diff --git a/net/udp/udp_finddev.c b/net/udp/udp_finddev.c
index b3ddb60c3d0..d47cb0b783b 100644
--- a/net/udp/udp_finddev.c
+++ b/net/udp/udp_finddev.c
@@ -105,11 +105,12 @@ FAR struct net_driver_s *udp_find_laddr_device(FAR struct udp_conn_s *conn)
 #endif
         {
           /* Make sure that the socket is bound to some non-zero, local
-           * address.  Zero is used as an indication that the laddr is
-           * uninitialized and that the socket is, hence, not bound.
+           * address.  The IPv6 unspecified address is used as an indication
+           * that the laddr is uninitialized and that the socket is, hence,
+           * not bound.
            */
 
-          if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr))
+          if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
             {
               return NULL;
             }
@@ -198,11 +199,12 @@ FAR struct net_driver_s *udp_find_raddr_device(FAR struct udp_conn_s *conn)
           if (net_is_addr_mcast(conn->u.ipv6.raddr))
             {
               /* Make sure that the socket is bound to some non-zero, local
-               * address.  Zero is used as an indication that the laddr is
-               * uninitialized and that the socket is, hence, not bound.
+               * address.  The IPv6 unspecified address is used as an
+               * indication that the laddr is uninitialized and that the
+               * socket is, hence, not bound.
                */
 
-              if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_allzeroaddr))
+              if (net_ipv6addr_cmp(conn->u.ipv6.laddr, g_ipv6_unspecaddr))
                 {
                   return NULL;
                 }