Force the speed and duplex of a Linux ethernet interface
Contributed by qmchenry 
Tagged: Linux networking Using mii-tool, the speed and duplex of an ethernet interface can be set manually.
You must set both the speed and duplex at the same time (it is not possible to auto-negotiate only one). Typical combinations are the following:
100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
To set 100 Mbps and full duplex on interface eth0, for example, use:
mii-tool -F 100baseTx-FD eth0
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