Rmon; Rmon Statistics - Cisco Small Business 200 Series Administration Manual

Status and Statistics

RMON

RMON
RMON (Remote Networking Monitoring) enables an SNMP agent in the device to proactively monitor traffic
statistics over a given period and send traps to an SNMP manager. The local SNMP agent compares actual,
real-time counters against predefined thresholds and generates alarms, without the need for polling by a
central SNMP management platform. This is an effective mechanism for proactive management, provided
that you have set the correct thresholds relative to your network's base line.
RMON decreases the traffic between the manager and the device since the SNMP manager does not have
to poll the device frequently for information, and enables the manager to get timely status reports, since the
device reports events as they occur.
With this feature, you can perform the following actions:
• View the current statistics (from the time that the counter values were cleared). You can also collect
the values of these counters over a period of time, and then view the table of collected data, where
each collected set is a single line of the History tab.
• Define interesting changes in counter values, such as "reached a certain number of late collisions"
(defines the alarm), and then specify what action to perform when this event occurs (log, trap, or log
and trap).

RMON Statistics

The Statistics page displays detailed information regarding packet sizes and information regarding physical
layer errors. The information is displayed according to the RMON standard. An oversized packet is defined
as an Ethernet frame with the following criteria:
• Packet length is greater than MRU byte size.
• Collision event has not been detected.
• Late collision event has not been detected.
• Received (Rx) error event has not been detected.
• Packet has a valid CRC.
To view RMON statistics and/or set the refresh rate:
STEP 1
STEP 2
STEP 3
Cisco Small Business 200 Series Smart Switch Administration Guide
Click Status and Statistics > RMON > Statistics.
Select the Interface for which Ethernet statistics are to be displayed.
Select the Refresh Rate, which is the time period that passes before the interface
statistics are refreshed.
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