Administrator Guide

Z-Series Debugging and Diagnostics
This chapter describes debugging and diagnostics for the Z-Series platform.
Topics:
• Offline Diagnostics
• TRACE Logs
• Last Restart Reason
• Hardware Watchdog Timer
• show hardware Commands
• Environmental Monitoring
• Buffer Tuning
• 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, they 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, they perform extensive tests on memory devices (for example,
SDRAM, flash, NVRAM, or 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. These diagnostics also perform snake tests using VLAN configurations.
Important Points to Remember
● 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.
Running Offline Diagnostics
To run offline diagnostics, use the following command.
1. Place the unit in the offline state.
EXEC Privilege mode
offline stack-unit
For normal system operation, reload the system after you issue the offline command.
NOTE: You cannot enter the command on a stacking unit.
56
780 Z-Series Debugging and Diagnostics