Extreme Networks ExtremeWare 7.7, Справочник по командам

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768 ExtremeWare 7.7 Command Reference Guide
Commands for Status Monitoring and Statistics
enable rmon
enable rmon
Description
Enables the collection of RMON statistics on the switch.
Syntax Description
This command has no arguments or variables.
Default
By default, RMON is disabled. However, even in the disabled state, the switch responds to RMON
queries and sets for alarms and events. By enabling RMON, the switch begins the processes necessary
for collecting switch statistics.
Usage Guidelines
The switch supports four out of nine groups of Ethernet RMON statistics. In an enabled state, the
switch responds to the following four groups:
• Statistics—The RMON Ethernet Statistics group provides traffic and error statistics showing packets,
bytes, broadcasts, multicasts, and errors on a LAN segment or VLAN.
• History—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-defined sample
intervals and bucket counters for complete customization of trend analysis.
• Alarms—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 auto calibrated or set manually.
• Events—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.
NOTE
You can use the RMON features of the system only if you have an RMON management application and
have enabled RMON on the switch.
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 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.