Viewing history using EDM

Ethernet history records periodic statistical samples from a network. A sample is called a history and is gathered in time intervals referred to as "buckets."

Histories establish a time-dependent method for gathering RMON statistics on a port. The default values for history are:

Both the time interval and the number of buckets is configurable. After the last bucket is reached, bucket 1 is dumped and "recycled" to hold a new bucket of statistics. Then bucket 2 is dumped.

Use the following procedure to view RMON history.

Prerequisites

Procedure steps


Step Action

1

From the navigation tree, double-click Serviceability.

2

In the Serviceability tree, double-click RMON.

3

In the RMON tree, double-click Control.

4

In the work area, click the History tab to view RMON history.


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Variable definitions

The following table describes the fields of the History tab.

Field Description
Index Indicates a unique value assigned to each interface. An index identifies an entry in a table.
Port Indicates an Ethernet interface on the device.
BucketsRequested Indicates the requested number of discrete time intervals over which data is to be saved in the part of the media-specific table associated with this entry.
BucketsGranted Indicates the number of discrete sampling intervals over which data is saved in the part of the media-specific table associated with this entry. There are instances after the actual number of buckets associated with this entry is less than the value of this object. In this case, at the end of each sampling interval, a new bucket is added to the media-specific table.
Interval Indicates the interval in seconds over which the data is sampled for each bucket in the part of the media-specific table associated with this entry. You can set this interval to a number of seconds between 1 and 3600 (1 hour). Because the counters in a bucket may overflow at their maximum value with no indication, note the possibility of overflow in the associated counters. Consider the minimum time in which a counter could overflow on a particular media type and set the historyControlInterval object to a value less than this interval. This interval is typically most important for the octets counter in a media-specific table. For example, on an Ethernet network, the etherHistoryOctets counter could overflow in about one hour at the Ethernet’s maximum utilization.
Owner Indicates the network management system that created this entry.

Creating a history using EDM

RMON can be used to collect statistics at intervals. For example, if switch performance is monitored over a weekend, enough buckets to cover two days must be set aside. To do this, set the history to gather one bucket each hour, thus covering a 48-hour period. After history characteristics are set, they cannot be modified; the history must be deleted and another created.

Use the following procedure to establish a history for a port, and set the bucket interval.

Procedure steps


Step Action

1

From the navigation tree, double-click Serviceability.

2

In the Serviceability tree, double-click RMON.

3

In the RMON tree, double-click Control.

4

In the work area, click the History tab.

5

In the toolbar, click Insert.

The Insert History dialog box appears.

6

In the fields provided, enter the information for the new RMON history.

7

Click Insert.


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Variable Definitions

The following table describes the fields of the Insert History dialog box.

Field Description
Index Indicates a unique value assigned to each interface. An index identifies an entry in a table.
Port Indicates any Ethernet interface on the device.
BucketsRequested Indicates the requested number of discrete time intervals over which data is to be saved in the part of the media-specific table associated with this entry.
Interval Indicates the interval in seconds over which the data is sampled for each bucket in the part of the media-specific table associated with this entry. You can set this interval to a number of seconds between 1 and 3600 (1 hour). Because the counters in a bucket may overflow at their maximum value with no indication, note the possibility of overflow in the associated counters. Consider the minimum time in which a counter could overflow on a particular media type and set the historyControlInterval object to a value less than this interval. This interval is typically most important for the octets counter in a media-specific table. For example, on an Ethernet network, the etherHistoryOctets counter could overflow in about one hour at the Ethernet’s maximum utilization.
Owner Indicates the network management system that created this entry.

Disabling history using EDM

Use the following procedure to disable RMON history on a port.

Procedure steps


Step Action

1

From the navigation tree, double-click Serviceability.

2

In the Serviceability tree, double-click RMON.

3

In the RMON tree, double-click Control.

4

In the History tab, select the row that contains the record you want to delete.

5

In the toolbar, click Delete.


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