Rmon Configuration; Working Mechanism - HP V1910 User Manual

RMON configuration

Remote Monitoring (RMON) is used for management devices to monitor and manage the managed devices
on the network by implementing such functions as statistics collection and alarm generation. The statistics
collection function enables a managed device to periodically or continuously track various traffic
information on the network segments connecting to its ports, such as total number of received packets or
total number of oversize packets received. The alarm function enables a managed device to monitor the
value of a specified MIB variable, log the event and send a trap to the management device when the value
reaches the threshold, such as the port rate reaches a certain value or the potion of broadcast packets
received in the total packets reaches a certain value.
Both the RMON protocol and the Simple Network Management Protocol (SNMP) are used for remote
network management:
RMON is implemented on the basis of the SNMP, and is an enhancement to SNMP. RMON sends

traps to the management device to notify the abnormality of the alarm variables by using the SNMP
trap packet sending mechanism. Although trap is also defined in SNMP, it is usually used to notify the
management device whether some functions on managed devices operate normally and the change of
physical status of interfaces. Traps in RMON and those in SNMP have different monitored targets,
triggering conditions, and report contents.
RMON provides an efficient means of monitoring subnets and allows SNMP to monitor remote

network devices in a more proactive, effective way. The RMON protocol defines an alarm threshold
on the managed device and when that threshold is reached, the managed device sends a trap to the
management device automatically. This method reduces the communication traffic between the
management device and the managed device because the management device does not need to
retrieve and compare the values of MIB variables multiple times. In this way, you can manage a large
scale of network easily and effectively.

Working mechanism

RMON allows multiple monitors (management devices). A monitor provides the following methods for data
gathering:
Using RMON probes. Management devices can obtain management information from RMON probes

directly and control network resources. In this approach, management devices can obtain all RMON
MIB information.
 Embedding RMON agents in network devices such as routers, switches, and hubs to provide the
RMON probe function. Management devices exchange data with RMON agents by using basic
SNMP operations to gather network management information, which, due to system resources
limitation, only covers four groups of MIB information alarm, event, history, and statistics, in most
cases.
The HP device adopts the second way and includes the RMON agent function. With the RMON agent
function, the management device can obtain the traffic flow among the managed devices on each
connected network segments and obtain information about error statistics and performance statistics for
network management.
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