ZyXEL Communications G-2000 Plus - Manual (Page 163)

ZyAIR G-2000 Plus User’s Guide
Chapter 12 Remote Management Screens 162
An agent is a management software module that resides in a managed device (the ZyAIR). An
agent translates the local management information from the managed device into a form
compatible with SNMP. The manager is the console through which network administrators
perform network management functions. It executes applications that control and monitor
managed devices.
The managed devices contain object variables/managed objects that define each piece of
information to be collected about a device. Examples of variables include such as number of
packets received, node port status etc. A Management Information Base (MIB) is a collection
of managed objects. SNMP allows a manager and agents to communicate for the purpose of
accessing these objects.
SNMP itself is a simple request/response protocol based on the manager/agent model. The
manager issues a request and the agent returns responses using the following protocol
operations:
• Get - Allows the manager to retrieve an object variable from the agent.
• GetNext - Allows the manager to retrieve the next object variable from a table or list
within an agent. In SNMPv1, when a manager wants to retrieve all elements of a table
from an agent, it initiates a Get operation, followed by a series of GetNext operations.
• Set - Allows the manager to set values for object variables within an agent.
• Trap - Used by the agent to inform the manager of some events.
12.6.1 Supported MIBs
The ZyAIR supports MIB II that is defined in RFC-1213 and RFC-1215. The focus of the
MIBs is to let administrators collect statistical data and monitor status and performance.
12.6.2 SNMP Traps
The ZyAIR will send traps to the SNMP manager when any one of the following events
occurs:
Table 53 SNMP Traps
TRAP # TRAP NAME DESCRIPTION
0 coldStart (defined in RFC-1215) A trap is sent after booting (power on).
1 warmStart (defined in RFC-1215) A trap is sent after booting (software reboot).
4 authenticationFailure (defined in
RFC-1215)
A trap is sent to the manager when receiving any
SNMP get or set requirements with the wrong
community (password).
6 whyReboot (defined in ZYXEL-
MIB)
A trap is sent with the reason of restart before
rebooting when the system is going to restart (warm
start).