The current requirements for the SNMP agents in an end system go beyond normal network management. They extend over system and application management up to the
management of middleware (transaction systems and databases). Because of the manifold requirements, with large end systems in particular, the desire arises to be able to employ a number of task-specific agents: this is supported by the structuring into master and agents.
The SNMP daemon is hierarchically above the agents. It provides basic functionality, such as handling the SNMP protocol, user access and security management, as well as connectivity to other agents. Note that the SNMP daemon can also be run as a stand-alone agent without being connected to any other agents. The SNMP daemon is therefore also responsible for outputting and setting the values of the various objects found in the MIB-II groups, as well as the ones found in other standardized MIBs (RFC 2272 - 2275).
The option of being able to start and stop agents separately simplifies the updating and use of individual agents without having to run the complete management system down. It also allows interrupt-free management of the remaining system if a component fails, as well as the parallel processing of different agent jobs.
The management station only communicates with the SNMP daemon. The SNMP daemon and agents communicate with each other via an asynchronous message interface. The asynchronous message interface guarantees high master agent performance with job processing because it is not blocked while processing lengthy jobs, but instead can process further SNMP requests in parallel.