Frame Check Sequence (FCS) errors

FCS errors indicate that frames of data are being corrupted.  FCS errors are counted when incoming frames fail the Cyclic Redundancy Check (CRC) test.  The number of FCS errors should be a very small percentage of the total data traffic.

Check the transceiver or controller card of the device connected to the port that is the source of the problem.  If the card appears to be operating correctly, check the cable and cable connections for breaks or damage.  Occasionally the problem may be caused by interference from other cables or machinery.