Monitoring Network Traffic

Using Traffic Monitor

Multicasts/sec: Represents the number of multicast packets being transmitted per second over the network or segment. Multicast packets are special forms of broadcast packets where copies of the packets are delivered to a subset of all devices on the network. This indicator gives an estimation of the amount of bulk communications which are taking place over the network. As with broadcast packets, this type of activity should be kept to a minimum as unicast messages use bandwidth much more efficiently.

Errors/sec: Represents the number of errors that have occurred for the network or segment. The number of errors can help you determine whether the network is functioning properly.

Reading the Traffic Information Gauges

The gauges display the network traffic information for the current minute. The colors on the gauges are:

■green: value for the attribute is within the normal range■yellow: value has exceeded the normal range, but is not critical■red: value is in the critical range. Corrective action may be needed.

■blue inner band: The “high water mark”, which shows you the highest value for that segment in the last hour. This indicator can help you determine if there are any transient or intermittent problems for the segment, even though the current minute indicator shows normal activity.

The amount of green, yellow and red displayed in each gauge corresponds to the threshold settings for that segment. For example, if Segment A is a 10Base-T segment, and the current Threshold settings for Utilization% are as follows,

green: OK, 0-50% utilizationyellow: warning, 51-75% utilizationred: critical, 76-100% utilization

then the gauge for Utilization% for Segment A would display a green area up to 50%, a yellow area from 51% to 75%, and a red area from 76% to 100%. Click on the Thresholds button to set segment thresholds.

The number in the rectangular box below the gauge indicates the attribute value for the current minute.

Reading the Segment Histogram

Each bar in the histogram represents a segment. The segments are displayed left to right in worst to best order, the worst segment being the one with traffic that most exceeds any threshold value for that segment. If there are more than 30 segments to be displayed, a scroll bar will allow you to scroll horizontally in order to view all the segments.

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