Answer
Interface management over SNMP is based on two tables:
- ifTable
- ifXTable (extension of ifTable)
Both are described in RFC 1213, Management Information Base for Network Management of TCP/IP-based internets: MIB-II and RFC 2233, The Interfaces Group MIB using SMIv2.
Interfaces can have several layers, depending on the media, and each sublayer is represented by a separate row in the table. The relationship between the higher layer and lower layers is described in the ifStackTable.
The ifTable defines 32-bit counters for inbound and outbound octets (ifInOctets/ifOutOctets), packets (ifInUcastPkts/ifOutUcastPkts, ifInNUcastPkts /ifOutNUcastPkts), errors, and discards.
The ifXTable provides similar 64-bit counters, also called high capacity (HC) counters, for inbound and outbound octets (ifHCInOctets/ifHCOutOctets) and inbound packets (ifHCInUcastPkts).
For a list of supported standard and enterprise-specific MIBs, click SNMP MIBs and Traps Reference.