Agents, Managers, and Subagents

The Simple Network Management Protocol (SNMP) is used by agents and managers to send and retrieve information. An agent is a software process that responds to SNMP queries to provide status and statistics about a network node. A manager is an application that manages SNMP agents on a network by issuing requests, getting responses, and listening for and processing agent-issued traps.

SNMP Communication

CIAgent uses a master agent/subagent architecture. The master agent is the agent protocol engine and performs the authentication, authorization, access control, and privacy functions. The master agent directs the retrieval and write processing and performs most of the trap processing. It also handles the connection or disconnection of subagents. When requests arrive, the master agent determines which subagents should receive the request.

Each SNMP agent or subagent implements a set of “managed objects.” These objects are described in management information base (MIB) documents written in the ASN.1 data description language.

Subagents perform the specific functions that collect or calculate values for each MIB object and pass that information to the master agent. Messages are passed asynchronously between the master agent and the subagent(s).

If the agents and subagents are able to retrieve the information, what controls the agents and subagents actions?

Next Topic: Managers