This article shows how to set and change the speed and duplexing of an Ethernet device. You can see more examples at “http://www.cyberciti.biz/faq/linux-change-the-speed-and-duplex-settings-of-an-ethernet-card/”.
View the current settings:
The output will be something similar to the following. Notice only physical network devices are listed.
eth0: negotiated 1000baseT-FD flow-control, link ok eth1: negotiated 100baseTx-FD, link ok eth2: negotiated 1000baseT-FD flow-control, link ok
You can set the speed and duplexing with the following example commands:
ethtool -s eth0 speed 10 duplex full ethtool -s eth0 speed 100 duplex full ethtool -s eth0 speed 1000 duplex full
The first of the above being 10MB/s and the second being 100MB’s. The third is Gigabit.
Note that virtual network devices such as “eth0:1” go by the physical device they’re associated with. So to change the settings for “eth0:1” you’d specify “eth0”.