SNMP Configuration and Management Manual

SNMP Configuration and Management Manual—424777-006
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Trap Multiplexer Subagent/Manager
The Trap Multiplexer is both a manager and a subagent. As a manager, the Trap
Multiplexer receives traps from network devices. It converts the traps into Event
Management Service (EMS) events, which can be accessed by NonStop management
applications or viewed on devices of different types. As a subagent, the Trap
Multiplexer interacts with the SNMP agent to provide SNMP manager access to its
MIB, which contains objects describing its trap conversion activities and its
configuration attributes.
This section describes the Trap Multiplexer, its MIB, and the events it generates. At the
end of this section a description of a sample application demonstrates how to
programmatically access trap-related information from events the Trap Multiplexer
generates when it receives traps.
Architectural Overview
As Figure 12-1 illustrates, the Trap Multiplexer interacts with TCP/IP processes to
receive traps and with the SNMP agent to receive and respond to SNMP requests.
Trap-to-Event Conversion
In its manager role, the Trap Multiplexer interacts with TCP/IP processes to collect
traps and with EMS to convert them into event messages.
The Trap Multiplexer collects traps from TCP/IP processes specified when you invoke
it. The UDP (User Datagram Protocol) port used for trap receipt from each TCP/IP
process is typically port 162, but this port number is configurable. In addition to
collecting traps from network devices, the Trap Multiplexer can collect traps sent to the
SNMP agent from SNMP subagents when a TCP/IP process from which the Trap
Multiplexer collects traps has been configured as a TRAPDEST object for the SNMP
agent. See Section 2, Installing and Configuring the SNMP Agent.
Although Figure 12-1 shows all TCP/IP processes on the same host as the Trap
Multiplexer, they can actually be on any NonStop host with which the system on which
the Trap Multiplexer is installed can communicate. Additionally, the Trap Multiplexer
can receive traps from a TCP/IP process being used for request/response messages
hosted by a SNMP agent process.
Using the EMS template in ZTMXTMPL, the Trap Multiplexer maps each trap into an
EMS event, which is then forwarded to the EMS collector specified when the Trap
Multiplexer is started. You can configure EMS to distribute events for access by
management applications or for viewing at a terminal, printer, or console device. Refer
to the EMS Manual for a complete description of how to configure and use EMS.
The subagent component of the Trap Multiplexer also generates events, which
describe noteworthy conditions related to the Trap Multiplexer process.