MII-TOOL(8)                 System Manager's Manual                MII-TOOL(8)

       mii-tool - view, manipulate media-independent interface status

       mii-tool  [-v, --verbose] [-V, --version] [-R, --reset] [-r, --restart]
       [-w,   --watch]   [-l,   --log]   [-A,   --advertise=media,...]    [-F,
       --force=media] [interface ...]

       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
       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.

       The default short output reports the negotiated  link  speed  and  link
       status for each interface.  If an interface or interfaces are not spec-
       ified on the command line,  then  mii-tool  will  check  any  available
       interfaces from eth0 through eth7.

       -v, --verbose
              Display  more  detailed  MII status information.  If used twice,
              also display raw MII register contents.

       -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
              instead 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.

       SIOCGMIIPHY on 'eth?' failed: Invalid argument
              If the interface is not running  (up),  kernel  will  refuse  to
              report 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

       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.

       David Hinds - dhinds@pcmcia.sourceforge.org
       Donald Becker - becker@scyld.com
       Bernd Eckenfels - ecki@debian.org

net-tools                     2004/03/28 23:30:00                  MII-TOOL(8)
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