how to change the auto-negotiation to yes in linux servers

Question

when I run the ethtool command on eth0 ( on VM machine redhat version 6.7 )

I see Supports auto-negotiation: No

can we change this to - auto-negotiation: yes ? , is it configurable?

 ethtool eth0
 Settings for eth0:
       Supported ports: [ TP ]
       Supported link modes:   1000baseT/Full
                            10000baseT/Full
       Supported pause frame use: No
       Supports auto-negotiation: No
       Advertised link modes:  Not reported
       Advertised pause frame use: No
       Advertised auto-negotiation: No
       Speed: 10000Mb/s
       Duplex: Full
       Port: Twisted Pair
       PHYAD: 0
       Transceiver: internal
       Auto-negotiation: off
       MDI-X: Unknown
       Supports Wake-on: uag
       Wake-on: d
       Link detected: yes

Answer 1

The

/etc/sysconfig/network-scripts/ifcfg-eth0

files can have the ethtool settings added to them so that the settings are saved and used every time the device is activated.

Config file option

ETHTOOL_OPTS="speed <100|1000|10000> duplex <half|full> autoneg <on|off>"

Add this line at the end of your configuration file :

ETHTOOL_OPTS="speed 1000 duplex full autoneg on"

and

/etc/init.d/network restart