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CompTIA Network+ N10-009 · Domain 5: Network troubleshooting

Switching issues: STP loops, incorrect VLAN assignment, ACLs

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Last reviewed September 25, 2026 · Leer en español

Once the physical layer is sound, Layer 2 switching configuration becomes the next common source of trouble. Network+ focuses on three issue types: spanning tree problems, VLAN mistakes and access control lists that block more or less than intended. They produce very different symptoms, from a whole building grinding to a halt to a single printer that cannot be reached, so learning to read the symptom tells you which to investigate first.

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