SNMP request processing

There are three types of request PDUs that can be received by the SNMP daemon.

The request types are defined in RFC 1157, and the PDUs all have the following format:

Table 1. Request PDU format
request-ID error-status error-index variable-bindings
GET 0 0 VarBindList
GET-NEXT 0 0 VarBindList
SET 0 0 VarBindList

The request-ID field identifies the nature of the request; the error-status field and error-index field are unused and must be set to 0 (zero); and the variable-bindings field contains a variable-length list of numeric-format instance IDs whose values are being requested. If the value of the request-ID field is SET, the variable-bindings field is a list of pairs of instance IDs and values.

Read Using the Management Information Base (MIB) Database in Communications Programming Concepts for a discussion of the three request types.