Switch Hardware Failure Issues

rule out physical hardware failure and Data Link layer issues before diagnosing Network layer or application issues

Power Issues

networks require stable power to operate properly
power anomalies can cause systems to lock up, reboot, or down everything
Uninterruptible Power Supplies (UPS) keep appliances running for a few minutes
- provides time to either switch to secondary power or shut down gracefully
most power problems will have to be escalated to an electrician or power company

consider components that might have experienced hardware failure
- host network adapters, switch/router/modem appliances, cabling
complete hardware failure is relatively uncommon
- verify driver is working correctly
easiest thing to do is replace the driver
for network appliances:
- use status LEDs to confirm operation
- check that plug-in cards are seated correctly
consider overheating as an issue
- ensure good airflow around intake and exhaust
- check fans and internals are not clogged with dust
- ensure system is not exposed to direct sunlight