How to Change Speed/Duplex of Ethernet Card Linux (Ethtool)

November 22, 2021

Ethtool\Variable to Permanently Set Ethtool Command Settings

Changes made with Ethtool are by default reverted after a system is re-booted. To apply custom settings each time a system boots edit the file for the device interface:

vi /etc/sysconfig/network-scripts/ifcfg-enp0s3

Add the desired values as a line at the end of the file using the following syntax:

ETHTOOL_OPTS="speed [100|1000|10000] duplex [half|full] autoneg [on|off]"

For example:

ETHTOOL_OPTS="speed 1000 duplex full autoneg on"

Save the changes and exit the file.

Now the changes are applied after every reboot and are permanent unless the file is altered again.

Origem: How to Change Speed/Duplex of Ethernet Card Linux {Ethtool Commands}