SNMP Configuration and Management Manual

The NonStop SNMP Environment
SNMP Configuration and Management Manual—424777-006
1-6
SNMP Subagent
SNMP agent is implemented, see Architectural Overview of NonStop SNMP on
page 1-14.
SNMP Subagent
Entity used by HP (and other vendors), in their SNMP implementations. SNMP
subagents handle a particular collection of resources. Some subagents are
implemented as independent processes, and some are bound into other processes,
such as the agent process. Some subagents, such as those shown in Figure 1-2, have
their own MIBs. Other subagents might implement multiple MIBs, or even share a MIB
with another subagent. Some subagents can reside on a system different from the
agent’s system. For details about each subagent HP currently offers, refer to Part II,
SCF for the SNMP Agent of this manual.
Toolkits
HP offers a Subagent Toolkit that helps programmers generate subagents that
interoperate with the SNMP agent. Subagents make customer-written NonStop
applications manageable by SNMP managers. For more information about the
Subagent Toolkit, refer to the SNMP Subagent Programmer’s Guide.
HP also offers a Manager Services toolkit that allows C and C++ programmers to
create SNMP managers that run as NonStop Kernel processes in either the Guardian
or in the Open System Services (OSS) environment. For information about Manager
Services, refer to the SNMP Manager Programmer’s Guide.
Message Protocol
In an SNMP environment, agents and managers communicate through the exchange
of three types of messages:
Each SNMP message contains a unit of information called a PDU. Five types of PDUs
are supported by any SNMP agent:
•
GetRequest
•
GetNextRequest
•
SetRequest (request PDUs)
•
GetResponse (response PDU)
•
Trap PDU
The format of SNMP messages is summarized in Figure 1-3 and described in more
detail in the following subsection.
Request messages Sent by a manager to initiate an action by an agent
Response messages Sent by an agent to respond to a manager’s request
Trap messages Sent by an agent to notify a manager of the occurrence of
significant events