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Rmon configuration, Rmon overview, Introduction – H3C Technologies H3C SecPath F1000-E User Manual

Page 140: Working mechanism

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RMON Configuration

This chapter includes these sections:

RMON Overview

Configuring the RMON Statistics Function

Configuring the RMON Alarm Function

Displaying and Maintaining RMON

Ethernet Statistics Group Configuration Example

History Group Configuration Example

Alarm Group Configuration Example

RMON Overview

Introduction

Remote Monitoring (RMON) is used for management devices to monitor and manage the managed
devices on the network by implementing such functions as statistics collection and alarm generation. The

statistics collection function enables a managed device to periodically or continuously track various

traffic information on the network segments connecting to its ports, such as total number of received

packets or total number of oversize packets received. The alarm function enables a managed device to

monitor the value of a specified MIB variable, log the event and send a trap to the management device

when the value reaches the threshold, such as the port rate reaches a certain value or the potion of
broadcast packets received in the total packets reaches a certain value.
Both the RMON protocol and the Simple Network Management Protocol (SNMP) are used for remote

network management:

RMON is implemented on the basis of the SNMP, and is an enhancement to SNMP. RMON sends
traps to the management device to notify the abnormality of the alarm variables by using the SNMP

trap packet sending mechanism. Although trap is also defined in SNMP, it is usually used to notify

the management device whether some functions on managed devices operate normally and the

change of physical status of interfaces. Traps in RMON and those in SNMP have different
monitored targets, triggering conditions, and report contents.

RMON provides an efficient means of monitoring subnets and allows SNMP to monitor remote
network devices in a more proactive, effective way. The RMON protocol defines that when an

alarm threshold is reached on a managed device, the managed device sends a trap to the

management device automatically, so the management device does not need to get the values of

MIB variables for multiple times and compare them, thus reducing the communication traffic

between the management device and the managed device. In this way, you can manage a large

scale of network easily and effectively.

Working Mechanism

RMON allows multiple monitors (management devices). A monitor provides two ways for data

gathering: