1-11 RMON ConfigurationWhen configuring RMON, go to these sections for information you are interested in:z RMON Overviewz Configuring the RMON Statistics Functionz Configuring the RMON Alarm Functionz Displaying and Maintaining RMONz RMON Configuration ExampleRMON OverviewThis section covers these topics:z Introductionz RMON GroupsIntroductionThe remote monitoring (RMON) is used to realize the monitoring and management from themanagement devices to the managed devices on the network by implementing such functions asstatistics and alarm. The statistics function enables a managed device to periodically or continuouslytrack various traffic information on the network segments connecting to its ports, such as total number ofreceived packets or total number of oversize packets received. The alarm function enables themanaged device to monitor the value of a specified MIB variable, log the event and send traps to themanagement device when the value reaches the threshold, such as the port rate reaches a certainvalue 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 remotenetwork management:z The RMON is implemented on the basis of the SNMP, which is thus enhanced. RMON sends trapsto the management device to notify the abnormality of the alarm variables by using the SNMP trappacket sending mechanism. Although trap is also defined in SNMP, it usually used to notify themanagement device whether some functions on the managed device operate normally and thechange of physical status of interfaces. Traps in RMON and in SNMP have different monitoredtargets, triggering conditions, and report contents.z RMON provides an efficient means of monitoring subnets and allows SNMP to monitor remotenetwork devices in a more proactive and effective way. The RMON protocol defines that when thealarm threshold is reached, the managed device send traps automatically, so the managementdevice has no need to get the values of MIB variables and compare them for multiple times, andthus greatly reducing the communication traffic between the management device and the manageddevices. In this way, you can manage a large scale of network easily and effectively.Working MechanismRMON allows multiple monitors. A monitor provides two ways of data gathering:
