Extreme Networks 300-48 Configuring RMON

RMON

Summit 300-48 Switch Software User Guide 143

The History group provides historical views of network performance by taking periodic samples o f 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.

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 can

be autocalibrated or set manually.

Alarms inform you of a network performance problem and can trigger automated action responses

through the Events group.

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, which provides a mechanism for an automated response to certain

occurrences.

Configuring RMON

RMON requires one probe per LAN segment, and standalone RMON probes traditionally have been

expensive. Therefore, Extreme’s approach has been to build an inexpensive RMON probe into the agent

of each system. This allows RMON to be widely deployed around the network without costing more

than traditional network management. The switch 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.

To enable or disable the collection of RMON statistics on the switch, use the following command:

[enable | disable] rmon

By default, RMON is disabled. However, even in the disabled state, the switch response to RMON

queries and sets for alarms and events. By enabling RMON, the switch begins the processes necessary

for collecting switch statistics.