How to determine the Link Speed or Network speed of a Network Adapter in Ubuntu

In order to determine the Link Speed or the Network Speed of a Network adapter in Ubuntu, simple open up a terminal window and issue the following command:

ethtool eth0

Here eth0 is your adapter name, it can be different than eth0. If you want to find out what your ethernet adapter is called give the following command

ifconfig -a

This will show you all the network adapters in your Ubuntu machine along with their names.

 

Operation not permitted ?!

I don't know why iḿ getting this(ubu1004): lee@lee-desktop:~$ ethtool eth0 Settings for eth0: Cannot get device settings: Operation not permitted Cannot get wake-on-lan settings: Operation not permitted Cannot get link status: Operation not permitted No data available