Chapter 44 Service Control

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

44.10.1Supported MIBs

The ZyWALL supports MIB II that is defined in RFC-1213 and RFC-1215. The ZyWALL also supports private MIBs (zywall.mib and zyxel-zywall-ZLD-Common.mib) to collect information about CPU and memory usage and VPN total throughput. The focus of the MIBs is to let administrators collect statistical data and monitor status and performance. You can download the ZyWALL’s MIBs from www.zyxel.com.

44.10.2 SNMP Traps

The ZyWALL will send traps to the SNMP manager when any one of the following events occurs.

Table 211 SNMP Traps

OBJECT LABEL

OBJECT ID

DESCRIPTION

Cold Start

1.3.6.1.6.3.1.1.5.1

This trap is sent when the ZyWALL is turned on or an

 

 

agent restarts.

 

 

 

linkDown

1.3.6.1.6.3.1.1.5.3

This trap is sent when the Ethernet link is down.

 

 

 

linkUp

1.3.6.1.6.3.1.1.5.4

This trap is sent when the Ethernet link is up.

 

 

 

authenticationFailure

1.3.6.1.6.3.1.1.5.5

This trap is sent when an SNMP request comes from

 

 

non-authenticated hosts.

 

 

 

 

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