I have recently bought gigabit network card Netgear GA311. Since I didn't
get a device driver on the CD I have downloaded a driver from Realtek's web
pages r1000 v1.05 because GA311 has Realtek's RTL8169S-32.

But when I try to set speed, duplex and autonegotiation using ethtool:

ethtool -s eth1 speed 1000 duplex full autoneg off

I get the following message:

Cannot set new settings: Operation not permitted
not setting speed
not setting duplex
not setting autoneg

Does anybody know what is wrong and how can I make it work?

Thanks in advance.