ZyXEL Communications G-2000 Plus User Manual

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ZyAIR G-2000 Plus User’s Guide
Chapter 12 Remote Management Screens
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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).