Configuring rmon, Overview, Rmon groups – H3C Technologies H3C MSR 5600 User Manual
Page 133: Statistics group, History group, Event group
120
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.
H3C 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, H3C implements the statistics group, history group, event group, alarm
group, probe configuration group, and user history group. H3C 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. For more
information about MIB settings for RMON, see Comware V7 Platform MIB Companion.
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, and 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,
and total number of packets.
The history table stores traffic statistics collected for each sampling interval.
Event group
The event group controls the generation and notifications of events triggered by the alarms defined in the
alarm group and the private alarm group. The following are RMON alarm event handling methods:
•
Log—Logs event information (including event time and description) in the event log table so the
management device can get the logs through SNMP.
•
Trap—Sends an SNMP notification to notify an NMS of the event.
•
Log-Trap—Logs event information in the event log table and sends SNMP notifications to the NMS.