ZyXEL P-663H-51 Guia Do Utilizador

Chapter 19 SNMP

P-663H-51 User’s Guide

An agent is a management software module that resides in a managed device (the ZyXEL 
Device). 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:

MIBs let administrators collect statistics and monitor status and performance. The ZyXEL 
Device supports the following MIBs:

• ADSL mib

• AT  mib

• ATM  mib

• ICMP  mib

• IP  mib

• SNMP  mib

• SYSOR mib

• TCP  mib

• UDP mib

The ZyXEL Device uses these MIBs to provide read-only information. You cannot use SNMP 
to configure the ZyXEL Device.

Table 52   SNMP Commands

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. 

Trap

 Used by the agent to inform the manager of some events.