mii-tool — Show/Check/Set the MII status.
MII (Media Independent Interface) is a standard bus which connects network interface controllers to physical media interfaces (PHYs). PHYs are usually located on a network interface card itself, but there are cards available which have external MII connectors for attaching external PHYs.
mii-tool display/checks/sets the status of a network interface’s MII unit. Most fast Ethernet adapters use an MII to autonegotiate link speed and duplex setting.
# mii-tool — Show shot status info about the network card.
# mii-tool -v — Show detailed status.
# mii-tool -R — Reset the MII unit to default value.
# mii-tool -r — Restart the Auto Negotiation.
# mii-tool -w — Watch the network interface and show if there is any change in the status.(Run it and remove & reconnect the cable).
# mii-tool -F 10baseT-HD — Forcibly set the capability to 10Mpbs and Half Duplex mode.
# mii-tool -A 10baseT-HD, 10baseT-FD — Enable and restart Auto Negotiation, and advertise only the specified capabilities.
Read: man mii-tool