Management Information Base (MIB)

Definition of Management Information Base (MIB) in The Network Encyclopedia.

What is MIB (Management Information Base)?

A hierarchical database that defines the information that an SNMP management system can request from an agent using Simple Network Management Protocol (SNMP).

How It Works

A Management Information Base (MIB) is a collection of manageable network objects. These objects are a logical representation of physical networking components that are SNMP-enabled (such as computers, hubs, routers, switches, and networking software). MIBs contain information about the configuration of these networking components, such as the version of the software running on the component, the IP address or port number, and the amount of available disk space for storage. MIBs function as a kind of directory containing the logical names of the network resources and their configuration parameters that are managed by SNMP.

Because every MIB is a member of the MIB hierarchy, you can uniquely identify a MIB for each network component. The name is represented using a standard dotted naming system. For example, the root of the LAN Manager MIB II in the following diagram would be represented by one of the following:


    Graphic M-2. The tree structure of a MIB.

This tree-link MIB structure contains branches both for public networking standard objects and proprietary private vendors’ implementations of networking objects. Vendors can apply to the Internet Assigned Numbers Authority (IANA) to have specific MIB numbers reserved for their products. For example, the LAN Manager MIB II has over 90 objects that SNMP management systems can use to obtain information about users who are logged on, sessions, shares, and so on.

You can use SNMP commands to retrieve the value of a MIB object or, in some cases, to change the value.


Microsoft’s implementation of SNMP in Windows NT and Windows 2000 includes the following MIBs, among others:

  • Internet MIB II:
    Objects for configuration analysis of TCP/IP networks


  • LAN Manager MIB II:
    Objects relating to sessions, shares, and users of LAN Manager–related software, including Windows NT and Windows 2000


    Objects for monitoring Dynamic Host Configuration Protocol (DHCP) statistics in Windows NT and Windows 2000


    Objects for monitoring Windows Internet Name Service (WINS) statistics in Windows NT and Windows 2000


MIB extensions exist for any SNMP-manageable device, including networking hardware and software from Apple, Cisco, Novell, and others.

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