Description

The article explains the commands used for fabric troubleshooting in MX480/960

Symptoms

Commands and steps explained to isolate fabric issue
show log messages
Show log chassisd
show chassis alarms
show fabric plane-location
show chassis fabric summary
show chassis hsl asic
Show chassis fabric plane
Show chassis fabric fpcs
Show chassis fabric map
Show chassis fabric map plane <>
show chassis fabric statistics <plane> totals detail
show chassis fabric statistics <plane> totals fpc
show chassis fabric statistics rates <plane> [summery|detail|fpc]
show chassis hsl channel asic-name CBXFY slot D errros
 

Solution

Following commands should give you error messages and tell you the issue is with which CB and a link between FPC:
show log messages (for the day issue occurred)
Show log chassisd (for the day issue occurred)
show chassis alarms (shows the date and time of the issue)

The errors will look something like this:
CHASSISD_FASIC_HSL_LINK_ERROR: Fchip (CB 2, ID 0): link 61 failed because of crc errors

Following commands show you basic information about fabric like its location and uptime and F chip ASICs:
show fabric plane-location
show chassis fabric summary
show chassis hsl asic

Following commands show you the status of the plane:
Show chassis fabric plane
Show chassis fabric fpcs

Following commands show you the connections between a plane and FPC:
Show chassis fabric map
Show chassis fabric map plane <>

Following commands show you the statistics for a plane:
show chassis fabric statistics <plane> totals detail <<for all FPC with a plane, this also shows you the link in error message
show chassis fabric statistics <plane> totals fpc <<for a particular FPC

Following commands show you the cell rate/drop  for a particular plane:
show chassis fabric statistics rates <plane> [summery|detail|fpc]

Following command shows you the CRC errors with the link on a particuler FPC:
show chassis hsl channel asic-name CBXFY slot D errros

1.  If all the links on a particular plane show errors, then replace
     the corresponding CB. (reset CB before replacing)
2.  If we have errors only on the links for a particular FPC, replace the FPC.
3.  If we take errors only on one (or some) of the links of a DPC on a
     particular plane, replace the Corresponding FPC with another FPC which has no error.

          3.1)If the errors move with the FPC, then replace the FPC.
          3.2)If the errors clear after reseating, the FPC, conclude that the FPC was not seated properly.
          3.3)If the errors stay with the same slot, then replace the CB.
          3.4)If the errors come back after replacing the CB and FPCs, replace the chassis.

 

Modification History

nothing has modified