H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 92)

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RMON
RMON overview
Remote Monitoring (RMON) is used to realize the monitoring and management from the management
devices to the managed devices on the network by implementing such functions as statistics and alarm.
The statistics 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, which is thus enhanced. 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 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 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.
NOTE:
For more information about RMON, see H3C WX3000E Series Wireless Switches Switching Engine
Configuration Guide. Figure 84
Configuring RMON
Configuring the RMON statistics function
RMON statistics function can be implemented by either the statistics group or the history group, but the
objects of the statistics are different. You can choose to configure a statistics group or a history group
accordingly.
• A statistics object of the statistics group is a variable defined in the Ethernet statistics table, and the
recorded content is a cumulative sum of the variable from the time the statistics entry is created to
the current time. Perform the tasks in Table 20 to configure RMON Ethernet statistics function.