Match each network troubleshooting scenario on the left with its most likely root cause on the right.
- A traceroute command successfully reaches the local default gateway, but all subsequent hops report 'Request timed out'.Upstream WAN gateway or ISP routing failure
- A laptop attempting 802.1X enterprise wireless authentication fails and disconnects immediately during the EAP negotiation phase.RADIUS server authentication or certificate misconfiguration
- Clients in a dense office environment report intermittent wireless degradation while Wi-Fi analyzers detect severe co-channel interference on channels 1, 6, and 11.Excessive Access Point density causing RF channel saturation
- A newly installed Cat 6 cable passes basic continuity testing with a simple wire mapper, but repeatedly drops speed from 1 Gbps to 100 Mbps under high traffic loads.Excessive untwisting of conductor pairs causing Near-End Crosstalk (NEXT)
Answer
Matching pairs: (1) Traceroute timing out after local gateway matches Upstream WAN gateway or ISP routing failure. (2) 802.1X wireless failure during EAP negotiation matches RADIUS server authentication or certificate misconfiguration. (3) Intermittent wireless degradation with co-channel interference matches Excessive Access Point density causing RF channel saturation. (4) Cat 6 cable dropping from 1 Gbps to 100 Mbps despite passing continuity testing matches Excessive untwisting of conductor pairs causing Near-End Crosstalk (NEXT).
Each scenario directly maps to its specific diagnostic signature: traceroute timeouts beyond the gateway signify ISP/WAN routing failures; EAP negotiation failures indicate RADIUS server or certificate errors; heavy utilization on channels 1, 6, and 11 demonstrates co-channel interference from high AP density; and gigabit speed degradation on continuity-tested cables stems from excessive pair untwisting leading to crosstalk (NEXT).
Step-by-Step Solution
Key Concept
Diagnosing physical, data link, and transport layer network issues in wired and wireless environments