This OID counts, in packets, how many inbound frames on this 100 Gbps Ethernet (100GbE) interface failed their CRC checksum or frame-alignment check. A CRC/alignment error means the frame was corrupted somewhere in transit, so a rising count here is a strong, packet-level signal of a physical or cabling problem on the link, distinct from congestion-related drops. For example, persistent CRC errors on a 100GbE line-side interface on a data-center-interconnect (DCI) link that don't clear after a card reboot would point an admin toward a bad cable, connector, or optical module rather than a software glitch.