Introduction

RMON (Remote Network Monitoring) provides standard information that a network administrator can use to monitor, analyze, and troubleshoot a group of distributed local area network. The standard information includes:

packets sent
bytes sent
packets dropped
statistics by host collected by conversations between two sets of addresses
certain kinds of events that have occurred

During the RMON, the managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Within a given MIB module, each object has a name, a syntax, an access-level, and an implementation-status. The name is an object identifier, an administratively assigned name, which specifies an object type. Refer to RFC 1757 “Remote Network Monitoring MIB“.

Some of the objects are specific to managing Ethernet networks. These are the objects in the etherStatsTable, the etherHistoryTable, and some attributes of the filterPktStatus and capturBufferPacketStatus objects.

Remote network monitoring devices, often called monitors or probes, are instruments that exist for the purpose of managing a network. Often these remote probes are stand-alone devices and devote significant internal resources for the sole purpose of managing a network.

The RMON provides:

Offline Operation—there are the conditions when a management station will not be in constant contact with its remote monitoring devices. During offline operation, the MIB allows a probe to be configured to perform diagnostics and collect statistics continuously, even when communication with the management station may not be possible or efficient (e.g. during an accident or by design for reducing the communication costs).
Proactive Monitoring—a monitor runs constant diagnostics and logs network performance. at the onset of any failure. It can notify the management station of the failure and store historical statistical information about the failure.
Problem Detection and Reporting—a monitor can be configured to recognize error conditions and check continuously for them. When one of these conditions occurs, the event may be logged, and management stations may be notified in a number of ways. Alarms can be set to raise awareness of the impending problems.
Data for Problem Solving—by highlighting the hosts on the network that generate the most traffic or errors, a probe can give the management station precisely the needed information for failure management.

The objects in the Management Information Base (MIB) are arranged in groups such as Ethernet statistics, history control, Ethernet history, alarm, host, hostTopN, matrix, filter, packet capture, and event. Each group is optional. If a remote monitoring device implements a group, then it must implement all objects in that group. For example, a managed agent that implements the host group must implement the hostControlTable, the hostTable, and the hostTimeTable. For more details, refer to RFC 1757 “Remote Network Monitoring MIB“.

For this configuration guide, we will cover enabling of the RMON module and configuring of Ethernet statistics, Ethernet history, Alarm, and Event Groups.

This chapter describes the purpose and scope of this document and the conventions used in this document.