MII-TOOL(8) Linux System Administrator's Manual MII-TOOL(8)
NAME
mii-tool - view, manipulate media-independent interface status
SYNOPSIS
mii-tool [-v, --verbose] [-V, --version] [-R, --reset] [-r, --restart]
[-w, --watch] [-l, --log] [-A, --advertise=media,...] [-F, --force=me-
dia] [-p, --phy=addr] interface ...
DESCRIPTION
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.
Most 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 op-
tions can be used to tell the MII to only advertise a subset of its ca-
pabilities. Some passive devices, such as single-speed hubs, are un-
able 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.
The default short output reports the negotiated link speed and link
status for each interface.
OPTIONS
-v, --verbose
Display more detailed MII status information. If used twice,
also display raw MII register contents.
Alert: If used three times, will force reading all MII regis-
ters, including non standard ones. It's not guaranteed any valid
answer from PHY while PHY communication can even hang. With
driver e1000e will fail while reading register 0x07.
-V, --version
Display program version information.
-R, --reset
Reset the MII to its default configuration.
-r, --restart
Restart autonegotiation.
-w, --watch
Watch interface(s) and report changes in link status. The MII
interfaces are polled at one second intervals.
-l, --log
Used with -w, records link status changes in the system log in-
stead of printing on standard output.
-F media, --force=media
Disable autonegotiation, and force the MII to either 100baseTx-
FD, 100baseTx-HD, 10baseT-FD, or 10baseT-HD operation.
-A media,..., --advertise=media,...
Enable and restart autonegotiation, and advertise only the spec-
ified media technologies. Multiple technologies should be sepa-
rated by commas. Valid media are 100baseT4, 100baseTx-FD,
100baseTx-HD, 10baseT-FD, and 10baseT-HD.
-p addr, --phy=addr
Override the MII address provided by kernel with value addr.
DIAGNOSTICS
SIOCGMIIPHY on 'eth?' failed: Invalid argument
If the interface is not running (up), kernel will refuse to re-
port its link state.
SIOCGMIIPHY on 'eth?' failed: Operation not permitted
Most kernels restrict access to root.
SIOCGMIIPHY on 'eth?' failed: No such device
This error is shown, if the kernel does not know about the named
device.
SIOCGMIIPHY on 'eth?' failed: Operation not supported
The interface in question does not support MII queries. Most
likely, it does not have MII transceivers, at all.
AUTHORS
David Hinds - dhinds@pcmcia.sourceforge.org
Donald Becker - becker@scyld.com
Bernd Eckenfels - net-tools@lina.inka.de
SEE ALSO
http://net-tools.sourceforge.net - Homepage of the net-tools project
net-tools 2013-02-15 MII-TOOL(8)