A network administrator is troubleshooting an issue where a workstation attached to Switch-A on port FastEthernet 0/5 experiences severe latency and dropped frames during file transfers to a server in the same VLAN on Switch-B. Switch-A logs indicate frequent speed and duplex mismatch alerts, and interface counters show a high count of late collisions on FastEthernet 0/5. Physical cable testing verifies the cabling is intact. The workstation's network interface is manually configured for 100 Mbps Full Duplex, whereas the switch port is set to auto-negotiation. Which of the following is the root cause of the performance degradation and frame loss on this link?
- Auto-negotiation on the switch interface defaulted to Half Duplex after failing duplex detection, resulting in a duplex mismatch with the host.Cevap
- BThe workstation and server reside in separate VLAN broadcast domains and require a Layer 3 device to establish full-duplex frame forwarding.
- CThe native VLAN configuration on the access port mismatches the server switch port, causing untagged host frames to be dropped by Switch-A.
- DSpanning Tree Protocol placed the interface into a blocking state because Switch-A was assigned a higher numerical priority than Switch-B.
Cevap
Auto-negotiation on the switch interface defaulted to Half Duplex after failing duplex detection, resulting in a duplex mismatch with the host.
When an end device interface is hardcoded to Full Duplex while the switch port auto-negotiates, auto-negotiation cannot establish duplex settings. The switch interface detects the 100 Mbps signal through parallel detection but defaults to Half Duplex in accordance with IEEE standards. The resulting duplex mismatch causes the full-duplex workstation to send frames regardless of line state, leading the half-duplex switch port to register late collisions, buffer congestion, and heavy packet loss.
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Anahtar Kavram
Duplex Mismatch and Auto-Negotiation Fallback