Debugging a 100G Standalone Switch

Effective debugging of a 100G standalone switch involves systematic physical checks, CLI diagnostics, port and VLAN verification, and monitoring real-time logs to isolate and resolve issues.

Initial Physical and Connectivity Checks

Start by inspecting the physical layer: ensure all cables are properly seated, SFP/SFP+ modules are compatible, and there is no visible damage to ports or connectors. Verify that link LEDs indicate proper connectivity and speed. For 100G ports, confirm that the transceivers support the required speed and that fiber or DAC cables meet specifications.

CLI Diagnostics and System Status

Use the switch's CLI to gather system information: System health: Check CPU, memory, fan status, temperature, and power supply using commands like get system status or equivalent for your switch model. Port status: Inspect all ports with commands such as get switch physical-port all to view link speed, duplex, admin status, and error counters.

VLA

N and configuration: Verify VLAN assignments, allowed VLANs, and STP state to ensure proper traffic segmentation.

Firmware and NT

P: Confirm firmware versions and NTP synchronization to avoid timing-related issues.

Real-

Time Debugging

Enable debug output for deeper analysis: Use diagnose debug enable and diagnose debug application to monitor specific daemons or protocols, such as DHCP or routing. Capture logs with timestamps to correlate events and identify intermittent issues.

For Forti

Switch or similar devices, monitor FortiLink or management interface communication if applicable.

Isolate and Test

Single port testing: Connect a test device directly to each port to verify throughput and link stability. Node-by-node verification: In complex topologies, test each switch or segment individually to locate bottlenecks or faulty hardware. Document findings: Maintain a spreadsheet of port assignments, IPs, and test results to track issues systematically.

Advanced Considerations

For high-performance 100G switches like NVIDIA SB77X0/SB78X0, check fabric congestion, adaptive routing, and subnet manager status to ensure optimal throughput.

Verify MA

Csec or encryption settings if using secure links, as misconfigurations can block traffic. Review recent configuration changes, firmware updates, or policy modifications that may have introduced the issue.

Summary

Debugging a 100G standalone switch requires a structured approach: start with physical inspection, gather system and port diagnostics via CLI, enable real-time debugging, isolate the problem to specific ports or VLANs, and document all findings. For complex or persistent issues, consult the switch vendor's administration guide and knowledge base for model-specific commands and troubleshooting procedures.