Enabling RMON1 History

About this task

Use RMON1 to establish a history for a port and configure the bucket interval. For example, to gather RMON statistics over the weekend, you must have enough buckets to cover two days. Configure the history to gather one bucket every hour, and cover a 48-hour period. After you configure the history characteristics, you cannot modify them; you must delete the history and create another one.

Procedure

  1. In the navigation pane, expand the Configuration > Serviceability > RMON folders.
  2. Click Control.
  3. In the History tab, click Insert.
  4. In the Port box, click the ellipsis (...) button.
  5. Select a port.
  6. Click OK.
  7. In the Buckets Requested box, type the number of discrete time intervals to save data.
  8. In the Interval box, type the interval in seconds.
  9. In the Owner box, type the owner information.
  10. Click Insert.

History Field Descriptions

Use the data in the following table to use the History tab.

Name

Description

Index

Specifies an index that uniquely identifies an entry in the historyControl table. Each entry defines a set of samples at a particular interval for an interface on the device. Index value ranges from 1–65535. The default value is 1.

Port

Identifies the source for which the system collects and places historical data in a media-specific table on behalf of this historyControlEntry. The source is an interface on this device. To identify a particular interface, the object identifies the instance of the ifIndex object, defined in (4,6), for the desired interface. For example, if an entry receives data from interface 1, the object is ifIndex 1. The statistics in this group reflect all packets on the local network segment attached to the identified interface. You cannot modify this object if the associated historyControlStatus object is equal to valid(1).

BucketsRequested

Specifies the requested number of discrete time intervals over which the system save data in the part of the media-specific table associated with this historyControlEntry. After this object is created or modified, the probe configures historyControlBucketsGranted as closely to this object as possible for the particular probe implementation and available resources. Values range from 1–65535. The default value is 50.

BucketsGranted

Specifies the number of discrete sampling intervals over which the system save data in the part of the media-specific table associated with this historyControlEntry. After the associated BucketsRequested object is created or modified, the probe sets this object as closely to the requested value as possible for the particular probe implementation and available resources. The probe must not lower this value except as a result of a modification to the associated BucketsRequested object. Occasionally, 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, the system adds a new bucket to the media-specific table. After the number of buckets reaches the value of this object and the system is going to add a new bucket to the media-specific table, the agent deletes the oldest bucket associated with this entry so the system can added the new bucket. After the value of this object changes to a value less than the current value, entries are deleted from the media-specific table associated with this entry. The agent deletes the oldest of these entries so that their number remains less than or equal to the new value of this object. After the value of this object changes to a value greater than the current value, the system allows the number of associated media-specific entries to grow.

Interval

Specifies the interval in seconds over which the system samples data for each bucket in the part of the media-specific table associated with this historyControlEntry. You can set this interval between 1–3600 seconds (1 hour). Because the counters in a bucket can overflow at their maximum value with no indication, you must take into account the possibility of overflow in all of the associated counters. Consider the minimum time in which a counter can overflow on a particular media type, and then set the historyControlInterval object to a value less than this interval, which is typically most important for the octets counter in a media-specific table. For example, on an Ethernet network, the etherHistoryOctets counter can overflow in approximately 1 hour at the maximum utilization. You cannot modify this object if the associated historyControlStatus object is equal to valid. The default value is 1800.

Owner

Specifies the entity that configured this entry and uses the assigned resources.