RMON 5-23
About the RMON Groups
The IETF define nine groups of Ethernet RMON sta-
tistics. This section describes these groups, and
details how they can be used.
Statistics
The Statistics group provides traffic and error statis-
tics showing packets, bytes, broadcasts, multicasts
and errors on a LAN segment or VLAN.
Information from the Statistics group is used to
detect changes in traffic and error patterns in critical
areas of your network.
History
The History group provides historical views of net-
work performance by taking periodic samples of
the counters supplied by the Statistics group. The
group features user-defined sample intervals and
bucket counters for complete customization of trend
analysis.
The group is useful for analysis of traffic patterns
and trends on a LAN segment or VLAN, and to
establish baseline information indicating normal
operating parameters.
Alarms
The Alarms group provides a versatile, general
mechanism for setting thresholds and sampling
intervals to generate events on any RMON variable.
Both rising and falling thresholds are supported, and
thresholds can be on the absolute value of a vari-
able or its delta value. In addition, alarm thresholds
may be autocalibrated or set manually.
Alarms are used to inform you of a network perfor-
mance problem and they can trigger automated
action responses through the Events group.
Hosts
The Hosts group specifies a table of traffic and
error statistics for each host on a LAN segment or
VLAN. Statistics include packets sent and received,
octets sent and received, as well as broadcasts, mul-
ticasts, and error packets sent.
The group supplies a simple discovery mechanism
listing all hosts that have transmitted. The next
group, Hosts Top N, requires implementation of the
Hosts group.
Hosts Top N
The Hosts Top N group extends the Hosts table by
providing sorted host statistics, such as the top 20
nodes sending packets or an ordered list of all
nodes according to the errors they sent over the last
24 hours.