In a switched environment, typical issues include physical issues or hardware problems, Layer 2 issues, and configuration issues. Physical issues can include port failures, network interface card (NIC) failures, and port configuration issues.
Layer 2 issues can include links not properly trunking, CAM table inconsistencies (the CAM table is the table that stores all the MAC addresses and the ports associated with the MAC addresses), or spanning-tree issues.
Configuration issues can include these issues and inconsistencies in configuration such as VTP, VLANs, or Spanning Tree.
The following are three suggestions to general switch troubleshooting:
Become familiar with normal ...