H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 105)

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9
RMON Configuration
This chapter includes these sections:
z RMON Overview
z Configuring the RMON Statistics Collection Function
z Displaying and Maintaining RMON
z Ethernet Statistics Group Configuration Example
RMON Overview
Introduction
Remote Monitoring (RMON) is used to realize the monitoring and management of the management
devices on 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:
z Implemented on the basis of the SNMP, RMON is an enhancement of 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.
z RMON provides an efficient means of monitoring subnets and allows SNMP to monitor remote
network devices in a more proactive and 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 has no need to get the values of
MIB variables for multiple times and compare them, and thus greatly reduces 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 of data gathering:
z Using RMON probes. Management devices can obtain management information from RMON
probes directly and control network resources. In this approach, Management devices can obtain
all RMON MIB information.