Reference Guide

S-Series Debugging and Diagnostics | 1067
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S-Series Debugging and Diagnostics
The chapter contains the following major sections:
• Offline diagnostics
• Trace logs
• Last restart reason (S4810 and S4820T)
• show hardware commands (S4810 and S4820T)
• Environmental monitoring
• Buffer tuning
• Troubleshooting packet loss
• Application core dumps
• Mini core dumps
• 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 (e.g., 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. These diagnostics also
perform snake tests using VLAN configurations.