Extreme Networks Summit1 - Manual (Page 192)

12-16 S UMMIT S WITCH I NSTALLATION AND U SER G UIDE
S TATUS M ONITORING AND S TATISTICS
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 configured 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
defined 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 notification.
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, Extreme’s 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.
For example, statistics can be related to individual ports. Also, because a probe must be
able to see all traffic, a stand-alone probe must be attached to a nonsecure port.
Implementing RMON in the switch means that all ports can have security features
enabled.
Summit.bk : 12STATUS.FM Page 16 Thursday, June 18, 1998 9:27 AM