Discovery

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The following sections describe how to discover SNMP-enabled devices:

Discovering SNMP-Enabled Devices

To discover a SNMP-enabled device:

  1. Go to the Discovery Control Panel page (System > Manage > Classic Discovery or System > Manage > Discovery in the classic user interface).
  2. In the Discovery Control Panel page, click Create.

  1. The Discovery Session Editor page appears. In the Discovery Session Editor page, supply values in the following fields:

  • Name. Enter a name for the discovery session. This name is displayed in the list of discovery sessions in the Discovery Control Panel page.
  • IP Address/Hostname Discovery List. Provide a list of the IP addresses or fully qualified domain names of the SNMP-enabled devices you want to discover.
  • SNMP Credentials. Select the SNMP credentials you created for the SNMP-enabled devices. You can select multiple credentials in this field.
  1. Optionally, supply values in the other fields in this page. For a description of the fields in this page, see the Discovery and Credentials section.
  2. Click Save.
  3. The Discovery Control Panel page will refresh. Click the lightning bolt icon () for the discovery session you just created.
  4. In the pop-up window, click OK. The page displays the progress of the discovery session.

Dynamic Application and Device Class Alignment

SL1 automatically aligns the correct device class and Dynamic Applications to each device during discovery.

The following sections describe how SL1 aligns Dynamic Applications and device classes.

How Does SL1 Align Dynamic Applications During Discovery?

Most Dynamic Applications include a discovery object. A discovery object enables SL1 to determine which devices to align with a Dynamic Application.

During discovery, SL1:

  1. Searches the list of Dynamic Applications.
  2. If a Dynamic Application includes a discovery object, SL1 adds that Dynamic Application to the list of Dynamic Applications to try to align during discovery.
  3. For each Dynamic Application that includes a discovery object, SL1 checks the current discovery session for an appropriate credential. For example, for each database Dynamic Application, SL1 would look for one or more database credentials that have been selected for the discovery session.
  4. For each discovered device, both those that support SNMP and those that don't, discovery tries to determine which Dynamic Applications to align. For each discovered device, SL1 tries to align each Dynamic Application in the list of Dynamic Applications to try during discovery. For each Dynamic Application in the list, SL1 tries to connect to each device with each of the appropriate credentials (until SL1 finds a working credential) and then tries to find the discovery object. If SL1 is able to connect to a device with one of the credentials and can then retrieve the discovery object, SL1 will align the Dynamic Application with the device.

NOTE: SL1 also includes more sophisticated logic that allows you to define multiple discovery objects, validate the value of the discovery object, and to align the Dynamic Application if a discovery object is not available. However, the most common use of a discovery object is as described above (discovery object exists).

  1. If discovery aligns a Dynamic Application with a device, immediately after discovery completes SL1 will start the first collection from that device using the aligned Dynamic Application. This step is not performed for Dynamic Applications that meet all of the following three criteria:
  • Has a collection frequency of 1 minute, 2 minutes, 3 minutes or 5 minutes.
  • Does not have component mapping enabled (does not discover component devices).
  • Is aligned with a component device.

NOTE: During discovery, SL1 tries each SNMP credential specified in the discovery session on each discovered device, to determine if SL1 can collect SNMP details from the device. Later in the discovery session, during alignment of Dynamic Applications, discovery again tries each SNMP credential specified in the discovery session. If one of the SNMP credentials times out three times without any response, discovery will stop trying to use that SNMP credential to align SNMP Dynamic Applications. Note that "no response" means that a device did not respond at all. Note that if a device reports that "no OID was found" or "the end of the OID tree was reached", these are considered a legitimate response and would not cause SL1 to abandon the credential.

How Does SL1 Align Device Classes During Discovery?

Device classes determine:

  • How devices are represented in the user interface
  • Whether the device is a physical device or a virtual device
  • How managed devices are discovered with the discovery tool

Administrators can define new or legacy device classes and customize properties of existing device classes on the Device Classes page (Devices > Device Classes), or on the Device Class Editor page (System > Customize > Device Classes) in the classic SL1 user interface.

Most TCP/IP-compliant devices have an internally-defined class ID, called the System Object ID and abbreviated to SysObjectID. This SysObjectID is an SNMP OID defined by the manufacturer. Each manufacturer specifies a SysObjectID for each different hardware model. In SL1, each SNMP device class is associated with a SysObjectID. During initial discovery, SL1 searches each device for the SysObjectID and assigns each device to the appropriate device class.

SL1 also includes device classes for devices that do not support SNMP. These device classes are associated with values returned by nmap. SL1 runs nmap against each device during discovery.

The following sections describe the types of device classes used in SL1.