Management Information Base (MIB)

This term describes the set of management information accessible through a network management protocol such as SNMP. SNMP uses a formal language to describe the MIB, called the Structure of Management Information (SMI). The current version of this language is SMIv2, described in IETF RFC 2578/STD 0047.

The elements of the MIB are named by Object Identifiers (OIDs). OIDs are vectors of non-negative integers structured hierarchically for uniqueness. They can be written numerically or symbolically. For example, the base OID of the 64-bit counter of octets received on an interface can be written as 1.3.6.1.2.1.31.1.1.1.6 (sometimes written with an additional leading dot), ifHCInOctets, IF-MIB::ifHCInOctets (showing the MIB module it was defined in), or iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifHCInOctets (sometimes with an additional leading dot). The OID hierarchy includes branches maintained by standards organizations such as the IETF, as well as many enterprise-specific branches used by specific vendors.

MIB definitions are structured as MIB modules. Usually, an individual "MIB file" includes the definition of a single MIB module. The term "MIB" is frequently used synonymously for "MIB module", although some hardcore SNMP veterans frown upon that usage.

-- SimonLeinen - 09 Aug 2009