Cable Issues

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• troubleshooting cable connectivity is at the Physical layer
• Ethernet link components:
  • Network transceiver in the host
  • patch cable between host and wall port
  • structured cable between wall port and patch panel (permanent link)
  • patch cable between the patch panel port and a switch
  • network transceiver in the switch port
• the entire cable path (patch cables + permanent link) is the channel link
• investigating link failure (complete loss of connectivity):
  • check the patch cables are properly terminated and connected
    • substitute with known good cable
  • test transceivers
    • use loopback tool to test for bad ports
  • test the structured cabling