A management information base (MIB) comprises a collection of objects in a (virtual) database used to manage entities (such as routers and switches) in a network. Objects in the MIB are defined using Abstract Syntax Notation One (ASN.1). The database is hierarchical (tree structured) and entries are addressed through object identifiers. Internet documentation RFCs discuss MIBs, notably RFC 1065, "Structure and Identification of Management Information for TCP/IP based internets", and its two companions, RFC 1066, "Management Information Base for Network Management of TCP/IP-based internets", and RFC 1067, "A Simple Network Management Protocol".

SNMP, a communication protocol between management stations (consoles, for example) and managed objects, (such as routers, gateways, and switches) makes use of MIBs. Components controlled by the management console need a so-called SNMP agent -- a software module that can communicate with the SNMP manager.

SNMP uses a specified set of commands and queries. An MIB should contain information on these commands and on the target objects (controlable entities or potential sources of status information) with a view to tuning the network transport to the current needs.

Examples of MIB objects include:

• output queue length, which has the name ifOutQLen
• Address Translation table (like ARP tables) called atTable.

RFC 1066 defines these as mandatory: if an environment does not use the atTable (as in the case of DDN-X.25 units) then the atTable simply remains empty. The table object includes, of course, definitions of table entries, atEntry and information about interfaces (if) for each atEntry, etc.

External links

• SimpleWeb MIBs index
• SNMP MIB Browser
• MIB index
• RFC 1213 - Management Information Base for Network Management of TCP/IP-based internets: MIB-II