Network discovery

Network Discovery discovers the internal IP networks and subnets within your organization.

Note: If you already know the IP address ranges in your network, it is not necessary to run Network Discovery. It is intended for organizations that do not have complete knowledge of the IP addresses available for Discovery in their networks.

How network discovery works

Discovery uses the information it gathers to update routers and Layer 3 switches in the CMDB. A single MID Server that begins its scan on a configurable list of starting (or seed) routers performs network Discovery. Typically, the starting routers are the default routers used by all the MID Server host machines in the network, but can be any designated routers. The MID Server uses the router tables on the starting routers to discover other routers in the network. The MID Server then spreads out through the network, using router tables it finds to discover other routers. It continues until all the routers and switches have been explored.

After running Network Discovery, convert the IP networks it finds into IP address Range Sets that you use in Discovery schedules to discover configuration items (CI).

Configure SNMP credentials or (optionally) SSH credentials. Port 161 must be open for SNMP access and port 22 for SSH access.

Network Discovery properties

The default values are correct for most discoveries. Navigate to Discovery Definitions > Properties to edit the properties.

Learn

What is network discovery?

Run network Discovery

Configure network Discovery from a Discovery schedule.

Before you begin

Role required: none

Configure SNMP credentials or (optionally) SSH credentials. Port 161 must be open for SNMP access and port 22 for SSH access.

Procedure

  1. Navigate to All > Discovery > Discovery Schedules.
  2. Click New and select Networks from the list in the Discover field.
  3. Select a MID Server.

    This field is mandatory.

  4. Complete the form, including the scheduling fields.
  5. Right-click in the header bar and select Save from the pop-up menu.

    The Related Links and related lists appear.

  6. Click Network Discovery Private IPs in Related Links to view the list of default private IP networks in the Discovery IP Ranges Related List.

    The default IP networks in this list are available to every Network Discovery you conduct and are sufficient for most discoveries.

  7. If your organization has additional private IP addresses, click New to add them.
    Figure 1. Private IP addresses
    Private IP addresses
  8. Add starting routers to the schedule in the Discovery Range Sets list.
    1. Click the Network Discovery Auto Starting Routers link to populate the list with the starting router for each MID Server in your network.
    2. Click Edit to add or delete routers from the list.
    Figure 2. Network Discovery schedule
    Network Discovery schedule
  9. Run Discovery manually, or through the scheduler.

Convert IP networks into Discovery range sets

After you conduct a network Discovery, you must convert the IP networks that were found into range sets for use in discovering other devices.

Before you begin

Role required: agent_admin or admin

Procedure

  1. Navigate to All > Discovery > Output and Artifacts > IP Networks.
  2. Click New to add an IP network.
  3. Ensure that the following field values are provided:
    • State: Ready
    • Discover: selected (true)
    • Router: Select a router from the list. This field must not be empty.
      If your IP Networks were created through network Discovery, then these fields are populated automatically in the IP Networks related list. However, if you entered the IP Networks manually, and you want to convert your IP Networks into range sets manually, you must edit these fields accordingly.
      Figure 3. IP network form
      IP network form
  4. Click Update to return to the list of IP Networks.
  5. In Related Links, click Create Range Sets.
    Use this feature to convert all the IP networks in the list into range sets.
    Figure 4. IP network list
    IP network list

    The Discovery Status page appears, displaying the progress of the conversion. The system increments the Started and Completed count of IP networks, until all the networks are converted.

What to do next

Add discovery range sets to Discovery schedules.

Add a Discovery range set to a Discovery schedule

After creating discovery range sets from a network discovery, add the sets to a discovery schedule. This process narrows down the range of IP addresses that Shazzam probes can scan. You can also add a behavior.

Before you begin

Role required: agent_admin or admin

Procedure

  1. Open a Discovery schedule.
  2. In the Discovery Range Sets related list, click Edit to add an existing range set and use the slushbucket to add the range set.
  3. On the Discovery schedule form, click the name of the range set under the Range column in the Discovery Range Sets related list.
  4. On the Discovery Range Set form, add a Discovery behavior if necessary.
    You can also activate or deactivate the range set for this schedule.
  5. Right-click the header, and then click Save.