− view, manipulate media-independent interface
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
intelligent network devices use an autonegotiation protocol
to communicate what media technologies they support, and
then select the fastest mutually supported media technology.
The −A or −−advertise
options can be used to tell the MII to only advertise a
subset of its capabilities. Some passive devices, such as
single-speed hubs, are unable to autonegotiate. To handle
such devices, the MII protocol also allows for establishing
a link by simply detecting either a 10baseT or 100baseT link
beat. The −F or −−force
options can be used to force the MII to operate in one mode,
instead of autonegotiating. The −A and
−F options are mutually exclusive.
short output reports the negotiated link speed and link
status for each interface. If an interface or interfaces are
not specified on the command line, then
mii−tool will check any available interfaces
from eth0 through eth7.
Display more detailed MII
status information. If used twice, also display raw MII
Display program version
Reset the MII to its default
Watch interface(s) and report
changes in link status. The MII interfaces are polled at one
Used with −w,
records link status changes in the system log instead of
printing on standard output.
Disable autonegotiation, and
force the MII to either 100baseTx-FD,
100baseTx-HD, 10baseT-FD, or 10baseT-HD
Enable and restart
autonegotiation, and advertise only the specified media
technologies. Multiple technologies should be separated by
commas. Valid media are 100baseT4,
100baseTx-FD, 100baseTx-HD, 10baseT-FD,
’eth?’ failed: Invalid argument
If the interface is not running
(up), kernel will refuse to report its link state.
’eth?’ failed: Operation not permitted
Most kernels restrict access to
’eth?’ failed: No such device
This error is shown, if the
kernel does not know about the named device.
’eth?’ failed: Operation not supported
The interface in question does
not support MII queries. Most likely, it does not have MII
transceivers, at all.
Donald Becker − firstname.lastname@example.org
Bernd Eckenfels − email@example.com