diff -ubdr linux-2.6.11-xen-sparse.orig/drivers/xen/netback/interface.c linux-2.6.11-xen-sparse/drivers/xen/netback/interface.c
--- linux-2.6.11-xen-sparse.orig/drivers/xen/netback/interface.c	2005-08-04 00:57:57.000000000 +0100
+++ linux-2.6.11-xen-sparse/drivers/xen/netback/interface.c	2005-11-25 15:18:21.000000000 +0000
@@ -65,6 +65,14 @@
     return 0;
 }
 
+static int net_change_mtu(struct net_device *dev, int new_mtu)
+{
+    if ((new_mtu < 68) || (new_mtu > 3000))
+           return -EINVAL;
+    dev->mtu = new_mtu;
+    return 0;
+}
+
 static void __netif_disconnect_complete(void *arg)
 {
     netif_t              *netif = (netif_t *)arg;
@@ -157,6 +165,7 @@
 
     dev->hard_start_xmit = netif_be_start_xmit;
     dev->get_stats       = netif_be_get_stats;
+    dev->change_mtu      = net_change_mtu;
     dev->open            = net_open;
     dev->stop            = net_close;
 
diff -ubdr linux-2.6.11-xen-sparse.orig/drivers/xen/netback/netback.c linux-2.6.11-xen-sparse/drivers/xen/netback/netback.c
--- linux-2.6.11-xen-sparse.orig/drivers/xen/netback/netback.c	2005-08-04 00:57:57.000000000 +0100
+++ linux-2.6.11-xen-sparse/drivers/xen/netback/netback.c	2005-11-25 19:36:39.000000000 +0000
@@ -510,7 +510,7 @@
         netif_schedule_work(netif);
 
         if ( unlikely(txreq.size < ETH_HLEN) || 
-             unlikely(txreq.size > ETH_FRAME_LEN) )
+             unlikely(txreq.size > 3018) )
         {
             DPRINTK("Bad packet size: %d\n", txreq.size);
             make_tx_response(netif, txreq.id, NETIF_RSP_ERROR);
diff -ubdr linux-2.6.11-xen-sparse.orig/drivers/xen/netfront/netfront.c linux-2.6.11-xen-sparse/drivers/xen/netfront/netfront.c
--- linux-2.6.11-xen-sparse.orig/drivers/xen/netfront/netfront.c	2005-08-04 00:57:57.000000000 +0100
+++ linux-2.6.11-xen-sparse/drivers/xen/netfront/netfront.c	2005-11-25 12:29:11.000000000 +0000
@@ -707,6 +707,13 @@
     return &np->stats;
 }
 
+static int network_change_mtu(struct net_device *dev, int new_mtu)
+{
+    if ((new_mtu < 68) || (new_mtu > 3000))
+           return -EINVAL;
+    dev->mtu = new_mtu;
+    return 0;
+}
 
 static void network_connect(struct net_device *dev,
                             netif_fe_interface_status_t *status)
@@ -969,6 +976,7 @@
     dev->hard_start_xmit = network_start_xmit;
     dev->stop            = network_close;
     dev->get_stats       = network_get_stats;
+    dev->change_mtu      = network_change_mtu;
     dev->poll            = netif_poll;
     dev->weight          = 64;