Cisco Systems SRW248G4PK9NA User Manual

Page of 483
Status and Statistics
Managing RMON
Cisco Small Business 300 Series Managed Switch Administration Guide 
18
2
 
Non-IP Rules
-
In Use—Number of TCAM entries used for non-IP rules.
-
Maximum—Number of available TCAM entries that can be used for non-
IP rules.
Managing RMON
RMON (Remote Networking Monitoring) is an SNMP specification that 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 the 
correct thresholds set relative to your network’s base line. 
RMON decreases the traffic between the manager and the device because the 
SNMP manager does not have to poll the device frequently for information, and 
enables the manager to get timely status reports, because the device reports 
events as they occur.
With this feature, you can perform the following actions:
View the current statistics (since 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).
Viewing RMON Statistics
The Statistics page
 
displays detailed information regarding packet sizes and 
information regarding physical layer errors. The information displayed is 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.