5-24 C HAPTER 5: A DVANCED M ANAGEMENTMatrixThe Matrix group shows the amount of traffic andnumber of errors between pairs of devices on a LANsegment or VLAN. For each pair, the Matrix groupmaintains counters of the number of packets,number of octets, and error packets between thenodes.The conversation matrix helps you to examine net-work statistics in more detail to discover who is talk-ing to whom or if a particular PC is producing moreerrors when communicating with its file server, forexample. Combined with Hosts Top N, this allowsyou to view the busiest hosts and their primary con-versation partners.FilterThe Filter group provides a mechanism to instructthe RMON probe to capture packets that match aspecific criterion or condition.CaptureThe Capture group allows you to create capturebuffers on the probe that can be requested anduploaded to the management workstation fordecoding and presentation.EventsThe Events group provides you with the ability tocreate entries in an event log and/or send SNMPtraps to the management workstation. Events canoriginate from a crossed threshold on any RMONvariable. In addition to the standard five trapsrequired by SNMP (link up, link down, warm start,cold start, and authentication failure), RMON addstwo more: rising threshold and falling threshold.Effective use of the Events group saves you time;rather than having to watch real-time graphs forimportant occurrences, you can depend on theEvent group for notification. Through the SNMPtraps, events can trigger other actions providing amechanism for an automated response to certainoccurrences.
