Linux add ethtool duplex settings to a network card permanently

In Debian or Ubuntu, it’s much easier to add a pre-up line to /etc/network/interfaces. Something like this:

iface eth0 inet static
pre-up /usr/sbin/ethtool -s $IFACE 10 duplex half
address ...

A few weeks ago, I did the same thing in SuSE as the switch in work reports the wrong settings.
Just add a script in /etc/sysconfig/network/scripts called ethtool-settings (for example) and link to it in /etc/sysconfig/network/if-up.d
The contents could be something like :-

/usr/sbin/ethtool -s eth0 speed 100 duplex full autoneg off

Noop, command is right. I have tested these commands lots of times. I have Intel NIC (e1000 driver) and it works w/o problem.

ethtool -s ethx autoneg off speed 1000 duplex full

Changing speed or duplex settings almost may require disabling auto negotiation with \’autoneg off\’. However you may need to turn on autoneg for 1000Mbps; it did work for my Intel card. But failed to work for other make NIC. So try both options.

Appreciate your post.

Hi,
i added a ethtool option (ETHTOOL_OPTS=”wol g”) in the file /etc/sysconfig/network-scripts/ifcfg-eth0 to have wol automatic enabled, but if i have eth0 configured with dhcp options i can’t get the “wol g” option active. On the contrary if i configure the eth0 nic with static ip address the ethtool option is well set.
I have a sme-server (CentOS based) and i’m going to be crazy to have wol g enabled with dhcp on… how can i get it to work?
Thanks,
Stefano – Italy

mii-tool is obsolete and it will be removed from future version or updates. You can easily install ethtool by running any one of the following command:

yum install ethtool

or (for rhel 4.x or older )

up2date -i ethtool

To automate mii-tool …
Add mii-tool command to /etc/rc.local with speed, which will run mii-tool on fly after Linux boots up. For eg following will set eth0 to 100Mbps FD

mii-tool -F 100baseTx-FD

HTH

simply superb

Debian:
/etc/network/interfaces

up ethtool -s eth0 speed 100 duplex full autoneg off

Worked for me. Our servers with out-of-the-box OS settings always went half-duplex during auto-negotiation with the router. So this line fixes that.
Ditto for ETHTOOL_OPTS line from article for Redhat.

A variant on the script that handles multiple interfaces and reads the interdfaces from a configuration file.

Enjoy.
Cheers

Interface entry in /etc/default/100Mbs:
INTERFACES=”eth0 eth1 eth3″

/etc/init.d/100Mbs startup script:#!/bin/sh
# Startup script for changing netowork interface parameters
#

ETHTOOL=”/usr/sbin/ethtool”
OPTIONS=”speed 100 duplex full autoneg off”

# Check for a configuration file in /etc/default
if [ ! -f /etc/default/100Mbs ]; then
echo “/etc/default/100Mbs does not exist! – Aborting…”
exit 1
fi

. /etc/default/100Mbs

case “$1″ in
start)
if test “$INTERFACES” != “”; then
for I in $INTERFACES; do
echo -n “Setting ${I} $OPTIONS …”;
$ETHTOOL -s ${I} $OPTIONS;
echo ” done.”
done
fi
;;
stop)
;;
esac
exit 0

Hi!! I have some question about this script, I’m enter in this script but some expression I don’t understand.
Well gooo.
#!/bin/sh
ETHTOOL=”/usr/sbin/ethtool”
DEV=”eth0″ // well here in the end the expression no coming “;” well in each expression.
SPEED=”100 duplex full”
case “$1″ in
start) //well here not is start()
echo -n “Setting eth0 speed 100 duplex full…”;
$ETHTOOL -s $DEV speed $SPEED;
echo ” done.”;;
stop) // here too stop ()
;;
esac
exit 0

well this script I’ll work but no change the base 100TX to 10T when restart my Debian, Now I’m use the tools like ethtool for change in the moment, well send me the solution and thank for the post is good information.