SNMP Interfaces

The SNMP Interface Monitor Entity editor supports the following entity types: group, equipment manager, port and interface. It also supports port and interface filters on groups and equipment manager objects.

If you check the Collect from ifXTable checkbox, then Open Manage Network Manager attempts to fetch attributes from the ifXTable. These attributes are ifHighSpeed, ifHCInOctets, ifHCInUcastPkts, ifHCOutOctets and ifHCOutUcastPkts. If any of these attributes are not available, then it fetches from ifTable.

If an interface does not support ifxTable, SNMP get typically retrieves an error and Open Manage Network Manager uses the ifTable instead. Some ATM ports do not send errors from the ifxTable oids, so Open Manage Network Manager also uses the ifTable values if ifHighSpeed is 0.

The SNMP V1 protocol does not support 64bit counters located in ifXtable. This means Open Manage Network Manager monitors only collect performance data from ifTable when a device is discovered using the SNMP V1 protocol. Best practice: Discover devices using snmpV2c or snmpV3 protocols to collect performance data located in ifXtable.

Even with this checked, Open Manage Network Manager defaulting to 32-bit counters if 64-bit is not available.

Open Manage Network Manager now supports multiple indexes in the SNMP Interface monitor. Specify them in the instance field, separated by dots. For sfpTxPowerValue, where Y is the slot and Z is the @ifindex, specify @slotNumber.@ifIndex as the instance. You can also specify a constant string. For sonetLineIntervalUASs X.16 Where X is the @ifindex and 16 is the last record, specify @ifIndex.16.


The variable name following the “@” must correspond to an attribute in the port or interface bean.



When determining the “not available” status of a device, SNMP AdminStatus and OperationalStatus messages both have to indicate a device is Available before a monitor determines it is available.

Certain devices that do not support ifTable availability indicators. For the sake of these devices, a Skip availability check checkbox appears.

The Skip Polling Interval configures skipped availability checks when polling, so you can check availability, for example, every fourth polling interval (skipping three). This helps the monitor avoid flutter artifacts

The PF and IF table columns indicate if a port filter or interface filter is configured for the entity. Click the icons on the right side of the list of Monitor Entities to configure filters. Clicking these buttons displays an interface configuration panel.

This panel lets you specify filter attributes for the port or interface filters you want to monitor. For example, if you select a device but only want to monitor active interfaces created by a particular user, then these filters do the job.

The SNMP Attributes panel is the same as described in SNMP.