diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 08f7b8295a7..fcebc699660 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -499,17 +499,14 @@ static int lo_rmmac(FAR struct net_driver_s *dev, FAR const uint8_t *mac)
  * Name: localhost_initialize
  *
  * Description:
- *   Initialize the Ethernet controller and driver
+ *   Initialize the localhost, loopback network driver
  *
  * Parameters:
- *   intf - In the case where there are multiple EMACs, this value
- *          identifies which EMAC is to be initialized.
+ *   None
  *
  * Returned Value:
  *   OK on success; Negated errno on failure.
  *
- * Assumptions:
- *
  ****************************************************************************/
 
 int localhost_initialize(void)
@@ -554,7 +551,7 @@ int localhost_initialize(void)
 #ifdef CONFIG_NET_IPv6
   net_ipv6addr_copy(priv->lo_dev.d_ipv6addr, g_lo_ipv6addr);
   net_ipv6addr_copy(priv->lo_dev.d_ipv6draddr, g_lo_ipv6addr);
-  net_ipv6addr_copy(priv->lo_dev.d_ipv6netmask, g_ipv6_alloneaddr);
+  net_ipv6addr_copy(priv->lo_dev.d_ipv6netmask, g_lo_ipv6mask);
 #endif
 
   /* Put the network in the UP state */
diff --git a/include/nuttx/net/loopback.h b/include/nuttx/net/loopback.h
index f2ebd7a6baa..dac01afec2e 100644
--- a/include/nuttx/net/loopback.h
+++ b/include/nuttx/net/loopback.h
@@ -51,17 +51,6 @@
 
 #ifdef CONFIG_NET_LOOPBACK
 
-/****************************************************************************
- * Public Type Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
-/****************************************************************************
- * Public Function Prototypes
- ****************************************************************************/
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -82,9 +71,15 @@ EXTERN const char           g_lo_hostname[];
 
 /* Local loopback addresses */
 
+#ifdef CONFIG_NET_IPv4
 EXTERN const in_addr_t      g_lo_ipv4addr;
 EXTERN const in_addr_t      g_lo_ipv4mask;
+#endif
+
+#ifdef CONFIG_NET_IPv6
 EXTERN const net_ipv6addr_t g_lo_ipv6addr;
+EXTERN const net_ipv6addr_t g_lo_ipv6mask;
+#endif
 
 /****************************************************************************
  * Public Function Prototypes
@@ -94,17 +89,14 @@ EXTERN const net_ipv6addr_t g_lo_ipv6addr;
  * Name: localhost_initialize
  *
  * Description:
- *   Initialize the Ethernet controller and driver
+ *   Initialize the localhost, loopback network driver
  *
  * Parameters:
- *   intf - In the case where there are multiple EMACs, this value
- *          identifies which EMAC is to be initialized.
+ *   None
  *
  * Returned Value:
  *   OK on success; Negated errno on failure.
  *
- * Assumptions:
- *
  ****************************************************************************/
 
 #ifdef CONFIG_NETDEV_LOOPBACK
diff --git a/net/loopback/lo_globals.c b/net/loopback/lo_globals.c
index 270fdb0b91b..d6be4a5ab31 100644
--- a/net/loopback/lo_globals.c
+++ b/net/loopback/lo_globals.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/loopback/lo_globals.c
  *
- *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2015, 2017 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -49,19 +49,31 @@
  * Public Data
  ****************************************************************************/
 
+#ifdef CONFIG_LIBC_NETDB
 /* Local loopback hostname */
 
 const char           g_lo_hostname[] = "localhost";
+#endif
 
 /* Local loopback addresses */
 
+#ifdef CONFIG_NET_IPv4
 const in_addr_t      g_lo_ipv4addr   = HTONL(0x7f000001);
 const in_addr_t      g_lo_ipv4mask   = HTONL(0xff000000);
+#endif
+
+#ifdef CONFIG_NET_IPv6
 const net_ipv6addr_t g_lo_ipv6addr   =
 {
   HTONS(0), HTONS(0), HTONS(0), HTONS(0),
   HTONS(0), HTONS(0), HTONS(0), HTONS(1)
 };
+const net_ipv6addr_t g_lo_ipv6mask   =
+{
+  HTONS(0xffff), HTONS(0xffff), HTONS(0xffff), HTONS(0xffff),
+  HTONS(0xffff), HTONS(0xffff), HTONS(0xffff), HTONS(0xffff)
+};
+#endif
 
 /****************************************************************************
  * Public Functions