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

NAME

       mii-diag - Network adapter control and monitoring

SYNOPSIS

       mii-diag [options]<interface>

DESCRIPTION

       This  manual  page documents briefly the mii-diag network adapter control and monitoring command.  Addition documentation is available from
       http://scyld.com/diag/index.html.

       This mii-diag command configures, controls and monitors the transceiver management registers for network interfaces, and configures  driver
       operational  parameters.  For transceiver control mii-diag uses the Media Independent Interface (MII) standard (thus the command name).	It
       also has additional Linux-specific controls to communicate parameters such as message enable settings and buffer sizes  to  the	underlying
       device driver.

       The  MII  standard defines registers that control and report network transceiver capabilities, link settings and errors.  Examples are link
       speed, duplex, capabilities advertised to the link partner, status LED indications and link error counters.

OPTIONS

       The mii-diag command supports both single character and long option names.  Short options use a single dash ('-') in front  of  the  option
       character.   For  options  without  parameters, multiple options may be concatenated after a single dash.  Long options are prefixed by two
       dashes ('--'), and may be abbreviated with a unique prefix.  A long option may take a parameter of the form --arg=param or --arg param.

       A summary of options is as follows.

       -A, --advertise <speed|setting>
	       -F, --fixed-speed <speed|setting>

	      Speed is one of: 100baseT4, 100baseTx, 100baseTx-FD, 100baseTx-HD, 10baseT, 10baseT-FD, 10baseT-HD.  For	more  precise  control	an
	      explicit numeric register setting is also allowed.

       -a, --all-interfaces
	      Show the status of all interfaces.  This option is not recommended with any other option, especially ones that change settings.

       -s,--status
	      Return exit status 2 if there is no link beat.

       -D     Increase the debugging level.  This may be used to understand the actions the command is taking.

       -g, --read-parameters
	      Show driver-specific parameters.

       -G, --set-parameters value[,value...]
	      Set driver-specific parameters.  Set a adapter-specific parameters.  Parameters are comma separated, with missing elements retaining
	      the existing value.

       -v     Increase the verbosity level.  Additional "-v" options increase the level further.

       -V     Show the program version information.

       -w, --watch
	      Continuously monitor the transceiver and report changes.

       -?     Emit usage information.

DESCRIPTION

       Calling the command with just the interface name (which defaults to capabilities, configuration and current status.

       The '--monitor' option allows scripting link beat changes.

       This option is similar to --watch, but with lower overhead and simplified output.  It polls the interface only once a second and the output
       format is a single line per link change with three fixed words
	 <unknown|down||negotiating|up> <STATUS> <PARTNER-CAP>

       Example output:	mii-diag --monitor eth0
	  down	       0x7809 0x0000
	  negotiating  0x7829 0x45e1
	  up	       0x782d 0x45e1
	  down	       0x7809 0x0000

       This may be used as
	 mii-diag --monitor eth0 |
	   while read linkstatus bmsr linkpar; do
	    case $linkstatus in
	       up)   ifup eth0 ;;
	       down) ifdown eth0 ;;
	    esac
	   done

       It  may	be  useful  to	shorten  the  DHCP  client  daemon  timeout  if  it does not receive an address by adding the following setting to
       /etc/sysconfig/network: DHCPCDARGS="-t 3"

SEE ALSO

       ether-wake(8),net-diag(8),mii-tool(8).
       Addition documentation is available from http://scyld.com/diag/index.html.

KNOWN BUGS

       The --all-interfaces option is quirky.  There are very few settings that are usefully applied to all interfaces.

AUTHOR

       The manual pages, diagnostic commands, and many of the underlying Linux network drivers	were  written  by  Donald  Becker  for	the  Scyld
       Beowulf(tm) cluster system.

Scyld Beowulf							 September 9, 2003						       MII-DIAG(8)