10-14
S
UMMIT
S
WITCH
I
NSTALLATION
AND
U
SER
G
UIDE
S
TATUS
M
ONITORING
AND
S
TATISTICS
H
ISTORY
The History group provides historical views of network performance by taking periodic
samples of the counters supplied by the Statistics group. The group features
user-deÞned sample intervals and bucket counters for complete customization of trend
analysis.
The group is useful for analysis of trafÞc patterns and trends on a LAN segment or
VLAN, and to establish baseline information indicating normal operating parameters.
A
LARMS
The Alarms group provides a versatile, general mechanism for setting threshold 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 variable or
its delta value. In addition, alarm thresholds may be autocalibrated or set manually.
Alarms inform you of a network performance problem and can trigger automated
action responses through the Events group.
E
VENTS
The Events group creates entries in an event log and/or sends SNMP traps to the
management workstation. An event is triggered by an RMON alarm. The action taken
can be conÞgured to ignore it, to log the event, to send an SNMP trap to the receivers
listed in the trap receiver table, or to both log and send a trap. The RMON traps are
deÞned in RFC 1757 for rising and falling thresholds.
Effective use of the Events group saves you time. Rather than having to watch real-time
graphs for important occurrences, you can depend on the Event group for notiÞcation.
Through the SNMP traps, events can trigger other actions, providing a mechanism for
an automated response to certain occurrences.
RMON
AND
THE
S
WITCH
RMON requires one probe per LAN segment, and standalone RMON probes have
traditionally been expensive. Therefore, ExtremeÕs approach has been to build an
inexpensive RMON probe into the agent of each Switch. This allows RMON to be
widely deployed around the network without costing more than traditional network
management. The Summit accurately maintains RMON statistics at the maximum line
rate of all of its ports.
SUMMIT.BK Page 14 Thursday, September 25, 1997 12:33 PM
