200-301: Cisco Certified Network AssociateDemo

An Ethernet frame that fails the FCS is counted as a CRC error because the received checksum does not match the frame contents. On Cisco interfaces, CRC errors are also part of the aggregate input error count, so both the specific CRC counter and the overall input errors counter increase. Size counters such as giants and runts change only when the frame length is invalid, and the frame counter is for alignment/framing-format problems rather than a standard FCS failure by itself.