[CentOS] Could not setup Speed and Duplex on CentOS 5.5

Fri Jan 7 15:02:47 UTC 2011
m.roth at 5-cent.us <m.roth at 5-cent.us>

Sikkandar Dulkarnai wrote:
> Greetings,
> I recently installed CentOS 5 on Dell PE 1750 server. I have noticed that
> the speed and duplex settings are 100 Half Duplex. I tried to change the
> duplex settings to full, but no success. I got the error message "Cannot
> get current device settings: Operation not supported". Does anyone else
> experience this issue?. Below is the error message and some more details
> about my box. Any help will be highly appreciated.
> [root at xentwo ~]# ethtool -s eth0 speed 100 duplex full autoneg on
> [root at xentwo ~]# ethtool -s eth0 speed 100 duplex full autoneg off

Not sure about the "can't get device settings", and I'm just not sure if
order is significant in the command, but the manpage, and past experience,
says that after the interface name, you *have* to have autoneg off,
otherwise forcing settings is a contradiction in terms.

The other question is what the switch you're connecting to is set to.