61200176L2-1 Express 4100/4110 User Manual C-1
Appendix C SNMP
Understanding SNMP
As Local Area Network (LAN) environments became standardized over
the past ten years, multi-vendor equipment grew with competition. It
became necessary to manage the various vendor equipment from a single
control console. Thus, the Simple Network Management Protocol
(SNMP) emerged as the de facto standard for managing commercial
Transmis sion Control Protocol/Internet Protocol (TCP/IP) networks.
The term SNMP broa dly refers to the message protocols used to exchange
information between th e n etwork an d the ma naged devices, as well as to
the structure of network management databases. SNMP has three basic
components:
•Network Manager: This is a control program that collects, controls,
and presents data pertinent to the operation of the network devices.
It resides on a ne twork manage ment stat ion.
•Agent: This is a control program that responds to queries and com-
mands fr om the network manager and returns r equested information
or invokes configuration changes initiated by the manager. It resides
in each network device connected.
•MIB: This is an index to th e organiz ed data within a network device.
It defines the operating parameters that can be controlled or moni-
tored.
When requesting the network manager to retrieve or modify a particular
piece of information about a network device, the network manager trans-
mits the request to that network device. The agent in that device inter-
prets the incoming request, performs the requested task, and sends its