mii-tool

This utility checks or sets the status of a network interface's Media Independent Interface (MII) unit. Most fast ethernet adapters use an MII to autonegotiate link speed and duplex setting.

• mii-tool [EN] @ Wikipedia

Documentation

• man 8 'mii-tool' [EN]

Examples

Check the link speed of al interfaces

mii-tool

Output:

eth0: negotiated 100baseTx-FD, link ok