Cisco Error Counters compared to SNMP error counters:
Some of the SNMP error counters are presented via the CLI, and other SNMP error counters are not. Also, Cisco will sometimes merge a number of error counters into general CLI error counters that remove valuable information and thus make troubleshooting more vague. As a result, querying the SNMP error counters is sometimes the only way to learn the specifics of errors that may or may not be presented via the CLI.
Here is Cisco’s documentation on how these error counters map to the “show interface” error counters:
Other error counters (Alignment Errors for example), are not available via the CLI and must be queried via SNMP to get the complete picture of errors/packets lost on an interface.