RMON stands for Remote Network Monitoring. It is an extension of the Simple Network Management Protocol (SNMP) that allows detailed monitoring of network statistics for Ethernet networks.
RMON was initially developed to address remote site and local area network (LAN) segment management from a centralized location. The RMON standard determines a group of functions and statistics exchanged between RMON compatible network probes and console managers.
There are two ROM Versions which are as follows −
It has defined 10 MIB groups for basic network monitoring. It operates on the MAC layer and the physical layer.
Statistics MIB Group − It contains a statistic measured by the probe for each monitored interface on this device. It includes statistics on packets dropped, packets sent, bytes, sent, broadcast packets, multicast packets, CRC errors, giants, packet fragments.
History − It records periodic statistical samples from a network and stores them for retrieval. It contains the number of samples, items sampled in different periods.
Alarm − It periodically takes statistical samples and compares them with the threshold set for events generation. It includes an alarm table & implementation of event group, Alarm type, interval, starting threshold, stop threshold.
HOST − It contains statistics associated with each host discovered on the network. Statistics contains Host address, packets & bytes that are received and transmitted, broadcast packets, multicast packets, error packets.
HOST top N − It prepares tables that describe the top hosts. It contains statistics on hosts, sample, and start and stop period, rate base duration.
Matrix − It stores and retrieves statistics for conversations between sets of two addresses. Its elements are source & destination address pairs, their packets, bytes & errors for each pair.
Filters − It enables packets to be matched by a filter equation for capturing packets or events. Its elements are bit-filter type, filter expression, conditional expression to other filters.
Packet Capture − It enables packets to be captured after they flow through a channel. Its elements are the buffer size for captured packets, full status, and the number of captured packets.
Events − It controls the generation and notification of events from a device. Its elements are event type, description, last time event sent.
Token ring − It supports token rings.
It operates on the above protocol layers of the OSI model: application, presentation, session, and transport & Network layer.
Protocol Delivery − It is a simple and interoperable way for an RMON 2 application to establish which protocols a particular RMON 2 agent implements.
Protocol Distribution − It maps the data collected by a probe to the correct protocol name displayed to the network manager.
Address Mapping − It helps address translation from the MAC layer to network layer addresses that are easier to read. It also supports the SNMP management platform and will lead to improved topology.
Network Layer host − It contains statistics for network layer traffic to or from each host.
Network Layer Matrix − It contains network layer traffic statistics for conversations between pairs of hosts.
Application Layer Host − It contains statistics for application layer traffic to or from each host.
Application Layer Matrix − It stores and retrieves application layer statistics for conversation between sets of two addresses.
Probe Configuration − It provides a standard way to remotely configure probe parameters such as trap destination and out-of-band management.
User History Collection − It contains periodic samples of user-specified variables.