Unknown SNMP devices are devices that can be accessed via SNMP, but that BMC Discovery has insufficient knowledge of to discover fully. Such devices might be switches, printers, and so on that are not defined in TKU.
The SNMP Recognition Rules page enables you to create rules for unknown SNMP devices so that they are identified in the future by BMC Discovery. From these rules, BMC Discovery can create SNMPManagedDevice, Printer, and Network Device nodes. The node type and capabilities are used to choose the correct class (
BMC_Printer, and so on) to model in the CMDB.
For BMC Discovery to recognize a device, appropriate SNMP credentials must be available, enabled, and valid for the IP address.
An approach is a way of recognizing a device. BMC Discovery uses real-world knowledge when offering possible recognition approaches. For example, if the sysObjectID states that the manufacturer is Xerox, then the device is almost certainly a printer. Similarly, Dell and HP printers always have printer in the sysDescr. The same practice is used for switches and load balancers. Where the device would be modeled as a Network Device node, you can always choose to create an SNMP Managed Device node instead.
In the sysDescr, you might be able to see information about the device. From there, the most appropriate recognition approach might be obvious; for example, where the sysDescr begins "Dell 1350cnw Color Printer" and the approaches offered are:
The approach most likely to be successful is "Printer (dell/printer)," although it is possible to use any listed.
Where SNMP devices are recognized using these recognition rules, they are not fully discovered as they would be with a TKU pattern. Rather, they provide a means of recognizing known device types.
The approach determined is the most likely to succeed but is not always correct. If the data has not been collected correctly, then you need to use the alternative generic approach provided; for example, (dell/generic) in the preceding example. If that also fails, the device cannot be discovered without adding support for it to a TKU. In this case, use the device capture to download the zipped MIB, and send it to the BMC Software Technology Update (TKU) team to request that support be included in BMC Discovery for that SNMP device.
The recognition approach does not work for some devices because they do not support the generic parts of the MIB that BMC Discovery queries. Where no device is created, the methods required to create one might have failed because the queries cannot be run against the unsupported generic parts of the MIB.
From the main menu, select Model > Devices.
The Model >Devices page opens.
The SNMP Managed Devices page shows the following information for each unrecognized SNMP device.
The number of this type of unrecognized device that have been detected.
|Inferred||The number of SNMP devices that have been created using this rule.|
The SNMP System Object ID of the SNMP managed device.
An excerpt from the SNMP system description.
Kind of device. For example, SNMP Managed Device, Printer, or Network Device.
The vendor of the SNMP managed device.
The model name of the SNMP managed device.
An dynamic list of available actions. The following are displayed depending on the Status as previously described:
Enter information about the device into the fields on the SNMP Recognition Rule dialog.
A read-only field showing the sysObjectID; also provides a link to a new Google search page for the sysObjectID.
A read-only field showing the sysDescr.
A drop-down list showing available recognition approaches. Select the one most appropriate for the device. For more information, see approach.
Enter the vendor of the device. This information can often be obtained from the sysDescr field. You cannot save the recognition rule without entering a Vendor name.
Enter the model name or number of the device. This information can often be obtained from the sysDescr field. You cannot save the recognition rule without entering a Model name.
Select the device capabilities from the drop-down list. For example, for the "Dell 1350cnw Color Printer", select Print. Where a device has multiple capabilities, click Add another and select from the new drop-down list. For example, a self-contained NAS might also have a Media Library, so you should select both of those capabilities.
Select an IP address from the drop-down list. This list is populated with the IP addresses that the unrecognized device has been reported on. Click Start to start the test.
Click Save to save the recognition rule.
The SNMP Recognition Rules page is displayed, and the status of the rule is now Rule Defined.
You can import or export recognition rules so you can transfer them between BMC Discovery instances.
Select the zipped recognition rules file and click Import.
The SNMP recognition rules file is imported.
If an SNMP Recognition Rule is exported and subsequently imported to the same BMC Discovery machine, any changes made to the rule in the UI between the export and import are overwritten without warning.
After you have created a recognition rule, you can scan the IP address.
If you delete a recognition rule that you have used to scan a device, the device is no longer unrecognized and does not appear on the SNMP Recognition Rules page. To create a new rule for the device, you must rescan it. Because there is no recognition rule in place (it was deleted), the device is unrecognized again and appears on the SNMP Recognition Rules page.
When you have developed SNMP recognition rules on a scanning appliance in a consolidating environment, you must also copy the recognition rules to any other scanning appliance in the consolidating environment.
For every other scanning appliance:
You do not need to copy the rules to consolidation appliances.