ARISTA-BRIDGE-EXT-MIB

TimeFilterTo be used for the index to a table. Allows an application to download only those rows changed since a particular time. Note that this is not a history mechanism. Only current values of underlying objects are returned; saved instance values associated with particular values of sysUpTime are not. An entry is considered changed if the value of any object in the entry changes, if the row is created, or if any object in the entry is created or deleted. Note that deleted entries cannot be detected or downloaded. A time-filtered conceptual table is created by inserting a single object of SYNTAX TimeFilter as the first INDEX component in a copy of an existing basic conceptual table (i.e., any SEQUENCE without a TimeFilter INDEX component). Thus, for each conceptual entry 'I' in the basic table, there exists N conceptual entries in the time-filtered version, indexed N.I, where 'N' is equal to the value of sysUpTime. When an application retrieves conceptual instances from a time-filtered table, and an INDEX value is provided for the TimeFilter INDEX component 'N', the agent will only consider returning basic conceptual entries (e.g., 'fooColumn.N.I') if any column within the basic conceptual entry has changed since sysUpTime 'N'. If not, the basic conceptual entry will be ignored for the particular retrieval operation. When sysUpTime is equal to zero, this table shall be empty. One conceptual entry exists for each past value of sysUpTime, except that the whole table is purged should sysUpTime wrap. As an entry in a time-filtered table is updated (i.e., one of the columns in the basic conceptual table is changed), new conceptual entries are also created in the time-filtered version (which still shares the now updated object values with all other instances). The number of unique time-filtered instances that are created is determined by the value of sysUpTime at which the basic entry was last updated. One unique instance will exist for each value of sysUpTime at the last update time for the row. However, a new TimeFilter index instance is created for each new sysUpTime value. The TimeFilter index values not associated with entry updates are called duplicate time-filtered instances. After some deployment experience, it has been determined that a time-filtered table is more efficient if the agent stops a MIB walk operation by skipping over rows with a TimeFilter index value higher than the value in the received GetNext/GetBulk request. That is, instead of incrementing a TimeFilter index value, the agent will continue to the next object or table. As a consequence, GetNext or GetBulk operations will provide only one pass through a time-filtered table. It is suggested that an agent implement a time-filtered table in this manner to improve performance and avoid a MIB walk getting stuck in time-filtered tables. It is, however, still acceptable for an agent to implement a time-filtered table in the traditional manner (i.e., every conceptual time-filtered instance is returned in GetNext and GetBulk PDU responses), and management applications must be able to deal with such traditional implementations. See the appendix for further discussion of this textual convention. The following example is provided to demonstrate TimeFilter behavior: Consider the following basic conceptual table, basicFooTable. (Note that the basic version of a time-filtered table may not actually be defined.) basicFooTable: basicFooTable ... INDEX { fooIndex } BasicFooEntry { fooIndex Integer32, fooCounts Counter32 } For this example, the basicFooTable contains two static conceptual entries (fooIndex equals '1' and '2'), created at time zero. It also contains one dynamic conceptual entry (fooIndex equals '3'), which is created at time '3' and deleted at time '7'. The time-filtered version of the basicFooTable could be defined as follows: FooTable: fooTable ... INDEX { fooTimeMark, fooIndex } FooEntry { fooTimeMark TimeFilter, fooIndex Integer32, fooCounts Counter32 } Note that entries exist in the time-filtered conceptual table only if they actually exist in the underlying (basic) table. For this example, the fooTable will have three underlying basic entries (fooIndex == 1, 2, and 3), with the following activity (for sysUpTime equal 0 to 9): - fooEntry.N.1 is created at time '0' and most recently updated at time '6' to the value '5'. - fooEntry.N.2 is created at time '0' and most recently updated at time '8' to the value '9'. - fooEntry.N.3 is created at time '3', updated at time '5' to the value '17', and deleted at time '7'. The following tables show the values that would be returned for MIB walk operations with various TimeFilter values, done at different times. An application issues a retrieval request at time 'T', with a TimeFilter value, 'N' (typically set to a lower value, such as the value of sysUpTime at the last polling cycle). The following values would be returned in a MIB walk of fooCounts.N if T equals '0' and N equals '0': fooCounts.N.I Value ========================== fooCounts.0.1 0 fooCounts.0.2 0 Note that nothing is returned for fooCounts.0.3, since that entry does not exist at sysUpTime equals '0'. The following values would be returned in a full (traditional) MIB walk of fooCounts.N if T equals '3' and N equals '0': fooCounts.N.I Value ======================= fooCounts.0.1 0 fooCounts.0.2 0 fooCounts.0.3 0 fooCounts.1.3 0 fooCounts.2.3 0 fooCounts.3.3 0 Note that there are no instances for T equals 1 or 2 for the first two values of N, as these entries did not change since they were created at time '0'. Note that the current value for 'fooCounts.N.3' is returned here, even for values of N less than '3' (when the entry was created). The agent only considers the current existence of an entry in the TimeFilter algorithm, not the time when the entry was created. Note that the instances 'fooCounts.0.3', 'fooCounts.1.3', and 'fooCounts.2.3' are duplicates and can be suppressed by the agent in a MIB walk. The following values would be returned in a full (traditional) MIB walk of fooCounts.N if T equals '6' and N equals '3': fooCounts.N.I Value ======================= fooCounts.3.1 5 fooCounts.3.3 17 fooCounts.4.1 5 fooCounts.4.3 17 fooCounts.5.1 5 fooCounts.5.3 17 fooCounts.6.1 5 Note that no instances for entry 'fooCounts.N.2' are returned, since it has not changed since time '3'. Note that all instances except 'fooCounts.5.3' and 'fooCounts.6.1' are duplicates and can be suppressed by the agent in a MIB walk. The following values would be returned in a full (traditional) MIB walk of fooCounts.N if T equals '9' and N equals '6': fooCounts.N.I Value ======================= fooCounts.6.1 5 fooCounts.6.2 9 fooCounts.7.2 9 fooCounts.8.2 9 Note that no instances for entry 'fooCounts.N.3' are returned, since it was deleted at time '7'. Note that instances 'fooCounts.6.2' and 'fooCounts.7.2' are duplicates and can be suppressed by the agent in a MIB walk. · TimeTicks

A TimeFilter that can be used to filter out entries that have not moved recently. If you don't want to filter, make sure to pass '0' for the value of this index component, otherwise pass the sysUpTime value representing the last time you queried the table.

Counter32

The number of times a given MAC address has changed ports without having been aged out, or the value 1 for a MAC address that was not previously in the table before being learned.

TimeTicks

The value of sysUpTime the last time the value of aristaDot1qTpFdbNumMoves was incremented.