Provided by: net-tools_1.60+git20161116.90da8a0-1ubuntu1_amd64 bug


       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] [-p, --phy=addr] 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


       -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 registers, 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

       -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  specified  media
              technologies.  Multiple technologies should be separated 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.


       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 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.


       David Hinds -
       Donald Becker -
       Bernd Eckenfels -

SEE ALSO - Homepage of the net-tools project