diff --git a/lwip/src/include/lwipopts.h b/lwip/src/include/lwipopts.h
index d21fe32c..9e9b36e8 100644
--- a/lwip/src/include/lwipopts.h
+++ b/lwip/src/include/lwipopts.h
@@ -37,7 +37,11 @@
 /**
  * LWIP_DHCP==1: Enable DHCP module.
  */
+#ifdef CONFIG_ROCKCREEK
+#define LWIP_DHCP		0
+#else
 #define LWIP_DHCP 		1
+#endif
 
 /**
  * DHCP_DOES_ARP_CHECK==1: Do an ARP check on the offered address.
@@ -68,7 +72,7 @@
  * when opening a connection. For the transmit size, this MSS sets
  * an upper limit on the MSS advertised by the remote host.
  */
-#define TCP_MSS			1460
+#define TCP_MSS			1440
 
 /**
  * TCP_SND_BUF: TCP sender buffer space (bytes).