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