Administrator Guide
Debugging and Diagnostics
This chapter describes debugging and diagnostics for the device.
Topics:
• Offline Diagnostics
• Trace Logs
• Auto Save on Crash or Rollover
• Last Restart Reason
• Hardware Watchdog Timer
• Using the Show Hardware Commands
• Enabling Environmental Monitoring
• Troubleshooting Packet Loss
• Enabling Application Core Dumps
• Mini Core Dumps
• Enabling TCP Dumps
Offline Diagnostics
The offline diagnostics test suite is useful for isolating faults and debugging hardware.
The diagnostics tests are grouped into three levels:
● Level 0 — Level 0 diagnostics check for the presence of various components and perform essential path verifications. In
addition, Level 0 diagnostics verify the identification registers of the components on the board.
● Level 1 — A smaller set of diagnostic tests. Level 1 diagnostics perform status/self-test for all the components on the board
and test their registers for appropriate values. In addition, Level 1 diagnostics perform extensive tests on memory devices
(for example, SDRAM, flash, NVRAM, EEPROM) wherever possible.
● Level 2 — The full set of diagnostic tests. Level 2 diagnostics are used primarily for on-board loopback tests and more
extensive component diagnostics. Various components on the board are put into Loopback mode and test packets are
transmitted through those components. Level 2 diagnostics also perform snake tests using virtual local area network (VLAN)
configurations.
Important Points to Remember
● You can only perform offline diagnostics on an offline standalone unit or offline member unit of a stack of three or more. You
cannot perform diagnostics on the management or standby unit in a stack of two or more; if you do, a message similar to this
displays: Running Diagnostics on master/standby unit is not allowed on stack.
● Diagnostics only test connectivity, not the entire data path.
● Diagnostic results are stored on the flash of the unit on which you performed the diagnostics.
● When offline diagnostics are complete, the unit or stack member reboots automatically.
Running Offline Diagnostics
To run offline diagnostics, use the following commands.
For more information, refer to the examples following the steps.
1. Place the unit in the offline state.
EXEC Privilege mode
offline stack-unit stack-unit-number
You cannot enter this command on a MASTER or Standby stack unit.
65
Debugging and Diagnostics 1033