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remote monitoring (RMON)

Remote Monitoring (RMON) is one of the most important extensions ofSNMP management. With RMON, it is possible to use analyzers in the network and make their information, such as traffic data, movement data and load behavior, available to SNMP.

RMON is a manufacturer and product independent tool, with which data networks can be managed like with a network monitor. RMON MIB is an extension of MIB II and defines the most important indicators for LAN segments in Ethernet and Token Ring, enabling uniform remote management in heterogeneous environments. This supports comprehensive fault diagnostics and statistics functions, enabling the network operator to monitor network performance and make network extensions as simple as possible.

RMON within the SNMP tree

RMON within the SNMP tree

The agent of RMON (Probes) can be deployed as a dedicated hardware component or in hubs, bridges, routes or personalcomputers(PCs). RMON exists in the first version as RMON1, whose functionality extends to the MAC layer. RMON1 cannot be used to make statements about subnet traffic or resolve addresses beyond a router. This contrasts with RMON2, which allows centralized measurement, monitoring and analysis beyond the MAC layer. RMON2 allows statements about application-dependent load balancing, subnet traffic volumes, and application-dependent load generation.

RMON groups for Ethernet and Token Ring

Statistics group, History group, Alarm group, Host group, HostTopN group, Matrix group, Filter group, Packet capture group, Event group, Ring station group.

The statistics group contains information about the usage as well as error statistics. The number of packets sent, packet size, broadcasts, multicasts, network errors and collisions are recorded.

TheHistory group provides trend analysis of usage based on the information from the Statistics group. In this group, counting operations are registered, which give conclusions about usage in a certain time interval and for certain data types.

In the alarm group, the user can configure alarms for each managed device. Custom alarm levels can be set for the values recorded by the RMON agent.

In the event group, rising and falling thresholds can be recorded and triggered accordingly for each event.

The host group consists of a statistics table based on MAC addresses. There are counters for broadcast, multicast and error packets as well as for the number of bytes. Information about both sent and received data for each host is included in this information.

The HostTopN group contains ordered host statistics. This group can be configured so that, for example, only the ten most active hosts are kept statistically. By reducing the number of hosts to the most important ones, the network traffic could be relieved accordingly because the data is reduced accordingly before transmission.

With the functions of the packet capture group, the operator can define the size of the buffer memories and change them according to the requirements of the data packet traffic.

In the traffic matrix group, the user and error information is presented in matrix form, in relation to a transmit and receive address. The operator thus receives information about the data traffic between specific network addresses and can draw conclusions from it.

With the filter group the operator can define specific filter functions. There is data filtering for selecting packets based on bit patterns and state filtering for selecting based on state information. With these techniques addresses, address groups, a special protocol as well as combinations of these possibilities can be selected.

Englisch: remote monitoring - RMON
Updated at: 09.04.2012
#Words: 551
Links: network, information, traffic, data, simple network management protocol (SNMP)
Translations: DE

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