diff --git a/components/net/lwip-1.4.1/src/core/dns.c b/components/net/lwip-1.4.1/src/core/dns.c
index 20398ae6099444a166e143d24924bb3b985b56ac..18c73d0a8cdad7d391f003a27e3d0a6715906359 100644
--- a/components/net/lwip-1.4.1/src/core/dns.c
+++ b/components/net/lwip-1.4.1/src/core/dns.c
@@ -279,11 +279,14 @@ dns_setserver(u8_t numdns, ip_addr_t *dnsserver)
     dns_servers[numdns] = (*dnsserver);
     
 #ifdef RT_USING_NETDEV
-      extern struct netdev *netdev_default;
+      extern struct netif *netif_default;
+      extern struct netdev *netdev_get_by_name(const char *name);
       extern void netdev_low_level_set_dns_server(struct netdev *netdev, uint8_t dns_num, const ip_addr_t *dns_server);
 
       /* set network interface device DNS server address */
-      netdev_low_level_set_dns_server(netdev_default, numdns, dnsserver);
+      if (netif_default) {
+        netdev_low_level_set_dns_server(netdev_get_by_name(netif_default->name), numdns, dnsserver);
+      }
 #endif /* RT_USING_NETDEV */
   }
 }
diff --git a/components/net/lwip-1.4.1/src/netif/ethernetif.c b/components/net/lwip-1.4.1/src/netif/ethernetif.c
index dfe304f91db334b8ec0911563d8f10c15ef3ef5b..7508ea0b87c0f05c4074a5a29780a50ed2cee794 100644
--- a/components/net/lwip-1.4.1/src/netif/ethernetif.c
+++ b/components/net/lwip-1.4.1/src/netif/ethernetif.c
@@ -99,6 +99,7 @@ static char eth_rx_thread_stack[RT_LWIP_ETHTHREAD_STACKSIZE];
 
 #ifdef RT_USING_NETDEV
 
+#include "lwip/ip.h"
 #include "lwip/init.h"
 #include "lwip/netdb.h"
 #include <netdev.h>
diff --git a/components/net/lwip-2.0.2/src/core/dns.c b/components/net/lwip-2.0.2/src/core/dns.c
index 5f8c3e52e333a6ffba6d1f42099cbbc8b2929942..c793b320a4588406f53fd69dd2e02ec1b650e712 100644
--- a/components/net/lwip-2.0.2/src/core/dns.c
+++ b/components/net/lwip-2.0.2/src/core/dns.c
@@ -370,11 +370,14 @@ dns_setserver(u8_t numdns, const ip_addr_t *dnsserver)
       dns_servers[numdns] = (*dnsserver);
         
 #ifdef RT_USING_NETDEV
-      extern struct netdev *netdev_default;
+      extern struct netif *netif_default;
+      extern struct netdev *netdev_get_by_name(const char *name);
       extern void netdev_low_level_set_dns_server(struct netdev *netdev, uint8_t dns_num, const ip_addr_t *dns_server);
 
       /* set network interface device DNS server address */
-      netdev_low_level_set_dns_server(netdev_default, numdns, dnsserver);
+      if (netif_default) {
+        netdev_low_level_set_dns_server(netdev_get_by_name(netif_default->name), numdns, dnsserver);
+      }
 #endif /* RT_USING_NETDEV */
     } else {
       dns_servers[numdns] = *IP_ADDR_ANY;
diff --git a/components/net/lwip-2.0.2/src/netif/ethernetif.c b/components/net/lwip-2.0.2/src/netif/ethernetif.c
index 6e0eb1eed762d70c36d7a9cf450a75ba22396b63..38e46de04647610b4785d4c826aa2043ccd345da 100644
--- a/components/net/lwip-2.0.2/src/netif/ethernetif.c
+++ b/components/net/lwip-2.0.2/src/netif/ethernetif.c
@@ -107,6 +107,7 @@ static char eth_rx_thread_stack[RT_LWIP_ETHTHREAD_STACKSIZE];
 
 #ifdef RT_USING_NETDEV
 
+#include "lwip/ip.h"
 #include "lwip/init.h"
 #include "lwip/netdb.h"
 #include <netdev.h>
diff --git a/components/net/lwip-2.1.0/src/core/dns.c b/components/net/lwip-2.1.0/src/core/dns.c
index 831956f7116b6941050e7cf33b08a94fe5960180..5129b7f3bc49911b457f3250ff2351141157e338 100644
--- a/components/net/lwip-2.1.0/src/core/dns.c
+++ b/components/net/lwip-2.1.0/src/core/dns.c
@@ -367,11 +367,14 @@ dns_setserver(u8_t numdns, const ip_addr_t *dnsserver)
       dns_servers[numdns] = (*dnsserver);
 
 #ifdef RT_USING_NETDEV
-      extern struct netdev *netdev_default;
+      extern struct netif *netif_default;
+      extern struct netdev *netdev_get_by_name(const char *name);
       extern void netdev_low_level_set_dns_server(struct netdev *netdev, uint8_t dns_num, const ip_addr_t *dns_server);
 
       /* set network interface device DNS server address */
-      netdev_low_level_set_dns_server(netdev_default, numdns, dnsserver);
+      if (netif_default) {
+        netdev_low_level_set_dns_server(netdev_get_by_name(netif_default->name), numdns, dnsserver);
+      }
 #endif /* RT_USING_NETDEV */
     } else {
       dns_servers[numdns] = *IP_ADDR_ANY;
diff --git a/components/net/lwip-2.1.0/src/netif/ethernetif.c b/components/net/lwip-2.1.0/src/netif/ethernetif.c
index 655f2864befa08be956504685d7c26e278219606..fd9db058e09732f39f72a46b82cce5c9a7159e1a 100755
--- a/components/net/lwip-2.1.0/src/netif/ethernetif.c
+++ b/components/net/lwip-2.1.0/src/netif/ethernetif.c
@@ -108,6 +108,7 @@ static char eth_rx_thread_stack[RT_LWIP_ETHTHREAD_STACKSIZE];
 
 #ifdef RT_USING_NETDEV
 
+#include "lwip/ip.h"
 #include "lwip/init.h"
 #include "lwip/netdb.h"
 #include <netdev.h>