11-2
Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter11 SNMP
SNMP Basic Components
Figure11-1 A basic network managed by SNMP
11.2 SNMP Basic Components
An SNMP-managed network consists of three primary c om pon ents: mana ged d ev ice s, age nt s, and
management systems. A managed device is a network node that cont ains an SNMP agent and resides on
an SNMP-managed network. Managed devices collect and store management informat ion and use
SNMP to make this information available to management systems that use SNMP. Managed devices
include routers, access servers, switches, bridges, hubs, computer hosts, and network elements such as
an ONS 15454.
An agent is a software module that resides in a managed device. An agent has local knowledge of
management information and translates that information into a form compatible with SNMP. The SNMP
agent gathers data from the MIB, which is the repository for device parameter and network data. The
agent can also send traps, or notification of certain events, to the manager. Figure11-2 illustrates these
SNMP operations.
Figure11-2 An SNMP agent gathering data from an MIB and sending traps to the manager
A management system such as HP OpenView executes applications that monitor and control managed
devices. Management systems provide the bulk of the processing and me mo ry re sou rces requ ire d f or
network management. One or more management systems must exist on any managed network.
Figure 11-3 illustrates the relationship between the three key SNMP components.
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get-next-request, get-bulk Network device
get-response, traps
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SNMP Manager
NMS
MIB
SNMP Agent