ethtool problem

Applications Programming
1

Hi,
I'm using ethtool to change network settings:
Just for the experiment, i want to change speed to 10, instead of 100,
I type:
ethtool -s eth0 speed 10 duplex full autoneg off

and to view settings i type:
ethtool eth0, and get this:

Settings for eth0:
Supported ports: [ TP AUI BNC MII FIBRE ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 10Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: external
Auto-negotiation: off
Link detected: yes

but if i type
ethtool eth0, after few seconds, it returns back to the old settings:
Settings for eth0:
Supported ports: [ TP AUI BNC MII FIBRE ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 1
Transceiver: external
Auto-negotiation: off
Link detected: yes

Am i doing something wrong?

Thanks,
Alex

2

Advertised auto-negotiation is on.

3

Thanks, but
Can i turn it off using ethtool?

4 
ETHTOOL(8)                                                          ETHTOOL(8)



NAME
       ethtool - Display or change ethernet card settings

SYNOPSIS
       ethtool ethX

       ethtool -h|--help

       ethtool -a|--show-pause ethX

       ethtool -A|--pause ethX [autoneg on|off] [rx on|off] [tx on|off]
...
5

Thanks,
but the line i used is:
ethtool -s eth0 speed 10 duplex full autoneg off

but i see it only changes
Auto-negotiation: off
but it leaves
Advertised auto-negotiation: Yes