Data Link Layer Troubleshooting

• Power Failure
• Switches not in the main Rack Room may not have UPS
• Bad Module
• GBIC – Gigabit Interface Converter
• SFP – Small Form-factor Pluggable
• Layer 2 Loop
• Address Table Corruption, Broadcast Storm, STP issues
• Port Configuration
• Speed, Duplex, MDIX
• VLAN Configuration
• Access vs Trunk and Wrong VLAN

Technology that allows swapping modules to test for problems