A network technician is diagnosing several network performance and connectivity issues across different departments in an enterprise environment. Match each observed diagnostic symptom to its most probable underlying root cause.
- A hardwired desktop experiences low throughput and high frame loss, with switch port counters showing a high number of late collisions.Duplex mismatch between the switch port and the host network interface card
- Wireless clients in a dense office area report frequent disconnects and latency spikes where adjacent access points broadcast on 2.4 GHz channel 6.Co-channel interference (CCI) causing wireless medium contention
- A workstation displays an IP address of 169.254.10.45 despite link status LEDs showing an active physical connection to the wall jack.DHCP server unreachability or scope exhaustion
- An optical network link between building switches suffers from severe signal degradation immediately after a patch cable was rerouted around a tight conduit corner.Exceeded optical fiber bend radius resulting in macrobending loss
Answer
Late collisions correspond to a duplex mismatch; overlapping 2.4 GHz access points correspond to co-channel interference; an APIPA IP address with an active link corresponds to DHCP server unreachability; and optical signal drop following a sharp cable routing bend corresponds to exceeded fiber bend radius.
Each diagnostic symptom directly maps to its specific Layer 1 or Layer 2 physical or protocol failure mode: late collisions indicate an Ethernet duplex mismatch; identical channel deployment across APs causes wireless co-channel interference; an APIPA address with link light activity points to unassigned DHCP settings; and tight physical bending of fiber cables causes macrobending optical loss.
Step-by-Step Solution
Key Concept
Troubleshooting Layer 1 and Layer 2 Wired and Wireless Network Issues
Estimated Time:2m 0s