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Information About RMON
RMON is an Internet Engineering Task Force (IETF) standard monitoring specification that defines a set of statistics and functions that can be exchanged between RMON-compliant console systems and network probes. RMON provides comprehensive network-fault diagnosis, planning, and performance-tuning information.
The following figure shows a sample configuration of the RMON feature with the Simple Network Management Protocol (SNMP) agent in the switch. This monitors all the traffic flowing among all the switches on all connected LAN segments.
Figure 1. Remote Monitoring Sample
The switch supports these RMON groups (defined in RFC 1757):
Statistics (RMON group 1)—Collects Ethernet statistics (including Fast Ethernet and Gigabit Ethernet statistics, depending on the switch type and supported interfaces) on an interface.
History (RMON group 2)—Collects a history group of statistics on Ethernet ports (including Fast Ethernet and Gigabit Ethernet statistics, depending on the switch type and supported interfaces) for a specified polling interval.
Alarm (RMON group 3)—Monitors a specific management information base (MIB) object for a specified interval, triggers an alarm at a specified value (rising threshold), and resets the alarm at another value (falling threshold). Alarms can be used with events; the alarm triggers an event, which can generate a log entry or an SNMP trap.
Event (RMON group 9)—Specifies the action to take when an event is triggered by an alarm. The action can be to generate a log entry or an SNMP trap.
Because switches supported by this software release use hardware counters for RMON data processing, the monitoring is more efficient, and little processing power is required.
64-bit counters are not supported for RMON alarms.
Adds an event in
the RMON event table that is associated with an RMON event number.
an event number. The range is 1 to 65535.
a description of the event.
log keyword to
generate an RMON log entry when the event is triggered.
the owner of this event.
enter the SNMP community string used for this trap.
privileged EXEC mode.
Switch# show running-config
Verifies your entries.
Switch# copy running-config startup-config
(Optional) Saves your entries
in the configuration file.
What to Do Next
To disable an alarm,
no rmon alarmnumber global
configuration command on each alarm you configured. You cannot disable at once
all the alarms that you configured. To disable an event, use the
no rmon eventnumber global
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