ethtool is the standard Linux utility for controlling network drivers and hardware, particularly for wired Ethernet devices. It can be used to:
Most features are dependent on support in the specific driver. See the manual page for full information.
Bug reports should be sent to the maintainer, Ben Hutchings <bhutchings@solarflare.com>, and to the netdev mailing list <netdev@vger.kernel.org>.
See the development page.
Older versions are available in the Sourceforge 'gkernel' project.