Editing Management information base (section)

===SMIv2===
The second version of the SMI (SMIv2) is described in {{IETF RFC|2578}} and {{IETF RFC|2579}}. It enhances and adds to the SMIv1-specific data types, such as including bit strings, network addresses, and counters. Bit strings are defined only in SMIv2 and comprise zero or more named bits that specify a value. Network addresses represent an address from a particular protocol family.  Counters are non-negative integers that increase until they reach a maximum value and then return to zero. In SMIv1, a 32-bit counter size is specified. In SMIv2, 32-bit and 64-bit counters are defined.

SMIv2 also specifies information modules, which specify a group of related definitions. Three types of SMI information modules exist: MIB modules, compliance statements, and capability statements. 
* MIB modules contain definitions of interrelated managed objects.
* Compliance statements provide a systematic way to describe a group of managed objects that must be implemented for conformance to a standard.
* Capability statements are used to indicate the precise level of support that an agent claims with respect to a MIB group. An NMS can adjust its behavior toward agents according to the capabilities statements associated with each agent.