On Fri, 2010-08-20 at 09:36 +0200, Timo Schoeler wrote: > > I tried with Intel's most recent driver, it shows the same behaviour: > > [root at bla ~]# ip link set dev eth0 mtu 1576 > SIOCSIFMTU: Invalid argument > [root at bla ~]# ip link set dev eth1 mtu 1576 > [root at bla ~]# ip link show dev eth1 > 6: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1576 qdisc pfifo_fast > qlen 1000 > link/ether 00:30:48:xx:xx:xy brd ff:ff:ff:ff:ff:ff Try with "ethtool" > > While the first device (seen as eth0) does *not* allow to set a > > different MTU (tried with 1576 and 1546, both values I could use; I am > > forced to use values >1500 here due to protocol stuff), the second works > > without a problem. Some e1000 cards do not even have support for jumbo frames. Just maybe if yours is that case you may not be able to raise the mtu value no higher than 1500. John