Routine maintenance is the underpinning of any well run network. Through routine maintenance, consistency, predictability and standardization all result allowing the network to operate as expected and in times of fault, makes a better troubleshooting environment.

As part of any routine maintenance activity, Cisco provides several commands to help. One less known command is the SHOW DIAG command. This command provides diagnostic information about the router and its controllers and interfaces.

The show diag command returns the following information about a router and its interfaces/adaptors/modules:

  • Hardware version
  • Board revision
  • RMA number and history
  • Chassis serial number
  • Cisco field replaceable unit (FRU) number (a good identifiable part number for the device)
  • Cisco part number (the actual part number of the device)
  • Technical registers of the backplane, including power supply and temperature status (not readable by this command)
  • Ports built into the motherboard of the device
  • Hardware versions, serial numbers, and part numbers for WIC cards in the device
  • Part numbers, port information, and serial numbers for network modules (NMs) inserted in the device

In the day-to-day maintenance plan, this information is useful in answering the following questions:

  • What are the serial numbers of my routers? (inventory)
  • What are the part numbers for the network module in my router? How does this compare to my minimum configuration policies? Which of my routes have a T1 WIC card that's version 1 and not version 2?
  • If there's a hardware issue with all router motherboards that are version A0, do any of my routers have this mother board version?

Lets look at some sample output:

cell_pe1#show diag
Slot 0:
C2610 1E Mainboard Port adapter, 5 ports
Port adapter is analyzed
Port adapter insertion time unknown
EEPROM contents at hardware discovery:
Hardware Revision : 2.3
PCB Serial Number : JAD03428879 (3059475211)
Part Number : 73-2839-13
RMA History : 00
RMA Number : 0-0-0-0
Board Revision : A0
Deviation Number : 0-16418
EEPROM format version 4
EEPROM contents (hex):
0x00: 04 FF 40 00 91 41 02 03 C1 18 4A 41 44 30 33 34
0x10: 32 38 38 37 39 20 28 33 30 35 39 34 37 35 32 31
0x20: 31 29 82 49 0B 17 0D 04 00 81 00 00 00 00 42 41
0x30: 30 80 00 00 40 22 FF FF FF FF FF FF FF FF FF FF
0x40: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x50: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x60: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0x70: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF

WIC Slot 0:
Serial 2T (12in1)
Hardware revision 1.0 Board revision D0
Serial number 23855958 Part number 800-03181-01
Test history 0x0 RMA number 00-00-00
Connector type PCI
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 12 01 00 01 6C 03 56 50 0C 6D 01 00 00 00 00
0x30: 68 00 00 00 00 11 10 00 FF FF FF FF FF FF FF FF

WIC Slot 1:
Serial 2T (12in1)
Hardware revision 1.0 Board revision D0
Serial number 22420112 Part number 800-03181-01
Test history 0x0 RMA number 00-00-00
Connector type PCI
EEPROM format version 1
EEPROM contents (hex):
0x20: 01 12 01 00 01 56 1A 90 50 0C 6D 01 00 00 00 00
0x30: 68 00 00 00 00 09 11 00 FF FF FF FF FF FF FF FF

From the sample output above, you can see that the show diag command generates a lot of valuable information. However, you can save some time by paring down this information to tell you just what you need. To do so, you have a couple of options. Your first option is to specify a certain slot. For example, let's say you know that your interface of interest is in slot 0, and you only want diagnostics information for that slot. You would enter the following:

cell_pe1# show diag 0

Your second option is to use the pipe character ? to include, exclude, or begin output at a specified point. Let's say you want to view all serial numbers:

cell_pe1#sh diag | inc Serial
PCB Serial Number : JAD03428879 (3059475211)
Serial 2T (12in1)
Serial number 23855958 Part number 800-03181-01
Serial 2T (12in1)
Serial number 22420112 Part number 800-03181-01

We hope you find this helpful.

Comments powered by CComment

Did you learn something?
Did I save you time? 

Buy me a coffeeBuy me a coffee!