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Configuring RMON
Overview
Remote Network Monitoring (RMON) is an enhancement to SNMP. It enables proactive remote
monitoring and management of network devices and subnets. An RMON monitor periodically or
continuously collects traffic statistics for the network attached to a port on the managed device. The
managed device can automatically send a notification when a statistic crosses an alarm threshold, so the
NMS does not need to constantly poll MIB variables and compare the results.
RMON uses SNMP notifications to notify NMSs of various alarm conditions such as broadcast traffic
threshold exceeded. In contrast, SNMP reports function and interface operating status changes such as
link up, link down, and module failure. For more information about SNMP notifications, see "
HP devices provide an embedded RMON agent as the RMON monitor. An NMS can perform basic
SNMP operations to access the RMON MIB.
RMON groups
Among standard RMON groups, HP implements the statistics group, history group, event group, alarm
group, probe configuration group, and user history group. HP also implements a private alarm group,
which enhances the standard alarm group. The probe configuration group and user history group are
not configurable from the CLI. To configure these two groups, you must access the MIB.
Statistics group
The statistics group samples traffic statistics for monitored Ethernet interfaces and stores the statistics in
the Ethernet statistics table (ethernetStatsTable). The statistics include:
•
Number of collisions.
•
CRC alignment errors.
•
Number of undersize or oversize packets.
•
Number of broadcasts.
•
Number of multicasts.
•
Number of bytes received.
•
Number of packets received.
The statistics in the Ethernet statistics table are cumulative sums.
History group
The history group periodically samples traffic statistics on interfaces and saves the history samples in the
history table (etherHistoryTable). The statistics include:
•
Bandwidth utilization.
•
Number of error packets.
•
Total number of packets.
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