Index: linux-2.6.32.9/drivers/net/bcm63xx_enet.c
===================================================================
--- linux-2.6.32.9.orig/drivers/net/bcm63xx_enet.c	2010-02-28 18:18:37.000000000 +0100
+++ linux-2.6.32.9/drivers/net/bcm63xx_enet.c	2010-02-28 18:20:03.000000000 +0100
@@ -1526,7 +1526,7 @@
 	actual_mtu = mtu;
 
 	/* add ethernet header + vlan tag size */
-	actual_mtu += VLAN_ETH_HLEN;
+	actual_mtu += VLAN_ETH_HLEN + VLAN_HLEN;
 
 	if (actual_mtu < 64 || actual_mtu > BCMENET_MAX_MTU)
 		return -EINVAL;