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 af9426ecdd71ee239b6a4b44d85ca3a501ffebe7..5ea03a9ae86f1ddeeba1c8a3e15087c1c2c7902b 100755
--- a/components/net/lwip-2.1.0/src/netif/ethernetif.c
+++ b/components/net/lwip-2.1.0/src/netif/ethernetif.c
@@ -315,6 +315,7 @@ static int netdev_add(struct netif *lwip_netif)
 	
     /* Update netdev info after registered */
     netdev->flags = lwip_netif->flags;
+    netdev->mtu = lwip_netif->mtu;
     netdev->ops = &lwip_netdev_ops;
     netdev->hwaddr_len =  lwip_netif->hwaddr_len;
     rt_memcpy(netdev->hwaddr, lwip_netif->hwaddr, lwip_netif->hwaddr_len);