phpman > man > mii-tool(8)

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=media] [-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 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  de‐
       tecting  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 inter‐
       face.

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 registers, including non stan‐
              dard 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  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  technolo‐
              gies.   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.


DIAGNOSTICS
       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.


AUTHORS
       David Hinds - dhinds AT pcmcia.org
       Donald Becker - becker AT scyld.com
       Bernd Eckenfels - net-tools AT lina.de


SEE ALSO
       http://net-tools.sourceforge.net - Homepage of the net-tools project



net-tools                                    2013-02-15                                  MII-TOOL(8)