Rmon Groups - H3C S5500-EI series Operation Manual

Operation Manual – SNMP-RMON
H3C S5500-EI Series Ethernet Switches
agents with basic SNMP commands to gather network management information,
which, due to system resources limitation, may not cover all MIB information but
four groups of information, alarm, event, history, and statistics, in most cases.
The device adopts the second way. By using RMON agents on network monitors, an
NMS can obtain information about traffic size, error statistics, and performance
statistics for network management.

2.1.3 RMON Groups

Among the ten RMON groups defined by RMON specifications (RFC 1757), H3C series
Ethernet switches support the event group, alarm group, history group and statistics
group. Besides, H3C also defines and implements the private alarm group, which
enhances the functions of the alarm group. This section describes the five kinds of
groups in general.
I. Event group
The event group defines event indexes and controls the generation and notifications of
the events triggered by the alarms defined in the alarm group and the private alarm
group. The events can be handled in one of the following ways:
Logging events in the event log table
Sending traps to NMSs
Both logging and sending traps
No action
II. Alarm group
The RMON alarm group monitors specified alarm variables, such as statistics on a port.
If the sampled value of the monitored variable is bigger than or equal to the upper
threshold, an upper event is triggered; if the sampled value of the monitored variable is
lower than or equal to the lower threshold, a lower event is triggered The event is then
handled as defined in the event group.
The following is how the system handles entries in the RMON alarm table:
1) Samples the alarm variables at the specified interval.
2) Compares the sampled values with the predefined threshold and triggers events if
all triggering conditions are met.
Note:
If a sampled alarm variable overpasses the same threshold multiple times, only the first
one can cause an alarm event. That is, the rising alarm and falling alarm are alternate.
2-2
Chapter 2 RMON Configuration