LINKSTAT(1)                                                        LINKSTAT(1)


NAME
     linkstat - a Craylink monitoring tool

SYNOPSIS
     linkstat [-e|-x][-c] -a | -h | -r | hwgraph_filename


DESCRIPTION
     linkstat reports on router link performance and error rates.  It also
     reports error rates on the Hub chip Craylink network interface (NI) and
     I/O Interface (II) links.


OPTIONS
     -c   Report information continuously every five seconds.

     -e   Only report error rates, not performance information. This option is
          exclusive with -x.

     -x   Only report router ports or hub devices that have non-zero error
          rates. This option is exclusive with -e and only useful when used
          with -a, -h or -r.

     -a   Report on all links in the system.

     -h   Report only on hub devices.

     -r   Report only on router devices.

EXAMPLES
     To get information about a particular link, you might try something like

     # linkstat /hw/module/1/slot/n1/node/hub/mon
     Hub: /hw/module/1/slot/n1/node/hub/mon
      NI: Retries 0 (0/Min), SN errs 0 (0/Min), CB errs 0 (0/Min)
      II: SN errs 0 (0/Min), CB errs 0 (0/Min)

     SN errs refers to sequence number errors.  Some number of these is
     normal.  Do not be alarmed by SN error counts.  CB errs refers to
     checkbit errors.  None of these errors are fatal, but high checkbit error
     or retry counts may indicate a problem.

     # linkstat /hw/module/1/slot/r2/router/mon
     Router: /hw/module/1/slot/r2/router/mon
      Port 3:  Utilization: bypass 0%  receive 2%  send 2%
       Retries 71847 (6/Min), SN errs 116395 (19/Min), CB errs 31196
       (2/Min)
      Port 5:  Utilization: bypass 9%  receive 13%  send 20%
       Retries 25087 (2/Min), SN errs 497298 (38/Min), CB errs 30417650
       (2914/Min)
      Port 6:  Utilization: bypass 0%  receive 4%  send 3%
       Retries 46394 (4/Min), SN errs 6252865 (599/Min), CB errs 5557


       (0/Min)
     ---------------------------------------------------------------------

     This example is from a sick system.  The checkbit errors on port 5 are
     excessive.  All of the other numbers are within spec.  Send and receive
     utilizations indicate how much of a port's peak bandwith is being used.
     Bypass indicates what percentage of traffic is able to use the latency-
     reducing bypass feature of the router chip.

     # linkstat -a

     This example would display information about all of the links on the
     system.

RESTRICTIONS
     If there are no routers present, the linkstat -a output will include a
     message like this one:

     Cannot access /hw/module/*/slot/r*/router/mon:
     No such file or directory

     Do not be alarmed.


SEE ALSO
     xbstat(1m), nstats(1), sn(1), hwgraph(4).


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