How to troubleshoot RX CRC errors on switch ports?

Zyxel_Adam Posts: 369  Zyxel Employee
First Anniversary 10 Comments Friend Collector First Answer
edited April 30 in Other Topics

Receiving CRC (Cyclic Redundancy Check) errors on a switch port typically indicates an issue related to physical layer network problems.

Here are the steps you can take to troubleshoot and resolve these errors:

  1. Check Duplex Settings:
    • Ensure that the duplex settings are correctly matched on both ends of the connection. Mismatched duplex settings between connected devices can lead to increased collision rates and CRC errors.
  2. Replace the Ethernet Cable:
    • Sometimes, CRC errors are caused by faulty or damaged Ethernet cables. Try replacing the cable with another one that is known to work correctly on another port without CRC errors.
  3. For SFP or SFP+ Ports:
    • Before replacing any hardware, check the Digital Diagnostic Monitoring (DDMI) information of the SFP or SFP+ module. DDMI provides critical information about the transceiver's status, including temperature, voltage, transmitted optical power, received optical power, and more. If abnormalities are detected through DDMI readings, consider replacing the transceiver or fiber cable.

If you encounter any other issues, please help create a post here and tag @Zyxel_CSO, or create a ticket directly to reach us.