diff --git a/bsp/at91sam9260/rtconfig.h b/bsp/at91sam9260/rtconfig.h
index f3caf7f7f2b95b5a04fa806f152ed1673f2fd2ef..dadcc3e6b0fcf59ba0cf94c973d10e4a56508b24 100755
--- a/bsp/at91sam9260/rtconfig.h
+++ b/bsp/at91sam9260/rtconfig.h
@@ -163,8 +163,6 @@
 /* Using DHCP */
 /* #define RT_LWIP_DHCP */
 
-#define RT_LWIP_DNS
-
 /* ip address of target */
 #define RT_LWIP_IPADDR0	192
 #define RT_LWIP_IPADDR1	168
diff --git a/bsp/mini2440/rtconfig.h b/bsp/mini2440/rtconfig.h
index d658dd681ee0fec95689c661d6f8b978ec066fac..c7fc987a05386919c9de1e308a7776c28e188622 100644
--- a/bsp/mini2440/rtconfig.h
+++ b/bsp/mini2440/rtconfig.h
@@ -151,8 +151,6 @@
 /* Using DHCP */
 /* #define RT_LWIP_DHCP */
 
-#define RT_LWIP_DNS
-
 /* ip address of target */
 #define RT_LWIP_IPADDR0	192
 #define RT_LWIP_IPADDR1	168
diff --git a/bsp/mini4020/rtconfig.h b/bsp/mini4020/rtconfig.h
index a92471f16fcb5d49c49e2ba7df2d9b04b94f55c7..b5a0d5194542255042ff9ab27f2001c63f5f4a7a 100644
--- a/bsp/mini4020/rtconfig.h
+++ b/bsp/mini4020/rtconfig.h
@@ -133,8 +133,6 @@
 /* Using DHCP */
 /* #define RT_LWIP_DHCP */
 
-#define RT_LWIP_DNS
-
 /* ip address of target */
 #define RT_LWIP_IPADDR0	192
 #define RT_LWIP_IPADDR1	168