How can InterMapper query a particular MIB variable?
There are two kinds of MIB variables: scalar values and table entries. • Scalars have a single value, such as the interface number shown above. For example, the ifNumber MIB variable of a router is a single number that represents the total number of its interfaces (ports). • Table values, on the other hand, provide the same pieces of information for different items, such as the traffic for each of a router’s ports, or information about each of the TCP connections in a device. InterMapper can read and display both scalar variables and table variables in its custom SNMP probes. Scalar values must have a “.0” suffix in their OIDs. For example, the OID for ifNumber in MIB-II is often written as “1.3.6.1.2.1.2.1”. In custom probe files, it should be represented as “1.3.6.1.2.1.2.1.0”. (This “.0” is technically part of the OID – it’s convenient not to write it, though.) Table variables are generally suffixed with the index of the row. (This isn’t always true: see the note below).
