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Zorluk: ZorWired and Wireless Network Issues

A workstation connected to a Fast Ethernet switch port experiences severe network performance degradation and slow file transfer speeds. An administrator inspects the switch port interface statistics and observes a continuous increase in late collisions and CRC frame errors. Further review shows that the switch port duplex mode was manually locked to 100 Mbps Full Duplex, while the workstation network adapter remains set to its factory default settings. Which of the following is the MOST likely cause of this network issue?

  1. The workstation network adapter is set to auto-negotiation, resulting in a duplex mismatch.Cevap
  2. B
    The workstation has self-assigned an APIPA address due to an unreachable DHCP server.
  3. C
    The switch port requires a Layer 3 router interface to process frame collision domain boundaries.
  4. D
    The network connection is suffering from 2.4 GHz adjacent channel interference.

Cevap

The workstation network adapter is set to auto-negotiation, resulting in a duplex mismatch.
When an Ethernet switch port is manually set to Full Duplex and the connected client network adapter is left on Auto-Negotiation, the client successfully detects the 100 Mbps link speed but cannot negotiate the duplex setting. Following Ethernet standards, the client defaults to Half Duplex. This results in a duplex mismatch where the switch sends data full-duplex (without checking for collisions) while the workstation transmits using CSMA/CD, producing heavy packet degradation, late collisions, and CRC frame errors.

Adım Adım Çözüm

1
Analyze the diagnostic symptoms on the switch port interface
The presence of late collisions and CRC errors indicates a data link duplex conflict on the physical connection.
Late collisions occur when a node detects a collision after transmitting the first 64 bytes of a frame, typical when one side operates in half-duplex while the other operates in full-duplex.
2
Evaluate Ethernet auto-negotiation standards
If one side of a Fast Ethernet link is manually forced to 100/Full, the peer configured for Auto-Negotiation senses the 100 Mbps speed but falls back to Half Duplex mode.
IEEE 802.3u standards dictate that if auto-negotiation pulses are not received from the link partner, the auto-negotiating node must default to half-duplex.
3
Determine the root cause and remediation step
The workstation NIC is operating in Half Duplex while the switch operates in Full Duplex, creating a duplex mismatch.
Matching both endpoints to either Auto-Negotiation on both sides or forcing 100 Mbps Full Duplex on both sides resolves the issue.

Anahtar Kavram

Ethernet Duplex Mismatch Diagnostics
Tahmini Süre:1m 30s
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Konular

Wired and Wireless Network Issues

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