This Counter32 object counts packets received by a port with a valid length but a bad frame check sequence with an integral number of bytes, indicating data corruption in transit. An admin chasing intermittent connectivity problems on a link watches this counter for growth as a sign of a bad cable, connector, or electrical interference. For example, a port with a steadily increasing FCS error count would prompt the admin to swap the cable or check for a nearby source of electromagnetic interference before suspecting the switch hardware itself.