Configure IP addresses in a Discovery schedule

Use one or more of these methods in any combination to define the network or network segment for Discovery to query.

Note: If you do not know the IP addresses in the network, run network discovery first to determine the IP networks. Then, convert the IP networks into IP address range sets.

IP address list

Use IP address lists to add individual addresses for Discovery to query. These addresses should not be included in any existing IP range or IP network. You can enter the IP address of the device or a host name (DNS name). If you enter a host name, it must be resolvable from the MID Server system.

IP address range

You can define arbitrary ranges of IP addresses for Discovery to query. This is a good way to include selected segments of a network or subnet. However, Discovery has no way of knowing if the IP range includes addresses for private networks or broadcast addresses and scans all the addresses in the range. If the network and broadcast addresses are included, then the results are inaccurate. For this reason, discoveries configured to detect IP networks are generally more accurate than those configured for IP address ranges. ServiceNow recommends that any IP address range only includes IP addresses reserved for manageable devices on the public network.

IP network

An IP network includes the range of available IP addresses in that network, including the network address (the lowest address in the range) and the broadcast address (the highest address in the range). An example of a class C network range is 192.168.0.0 to 192.168.0.255. In the Range Set form, this network can be entered with either of the following notations:
  • 192.168.0.0/24
  • 192.168.0.1/255.255.255.0

This notation indicates that Discovery is scanning an IP network, and Discovery does not scan the highest and lowest numbers in the range. This prevents significant errors from being introduced into the Discovery data by the broadcast address, which returns all the devices in the network, and the network address, which can add an arbitrary number of redundant devices. This built-in control makes IP networks the best method of defining which IP address ranges to query.

Examples of valid IP address ranges

Valid IP address ranges can be as follows:
  • An IP address in dotted decimal or hexadecimal format. The hexadecimal format can be explicitly prefixed with 0x, this is not mandatory. Here are examples:
    • 10.11.144.155
    • 0x0A0B909B
    • 0A0B909B
  • An IP address range in dotted decimal or hexadecimal format. Here are examples:
    • 10.11.144.150-10.11.144.160
    • 0x0A0B9096-0x0A0B90A0
    • 10.11.144.150-0x0A0B90A0
  • An IP network address with the net mask specified after a slash (/) in regular notation (0-32 inclusive) or in IP address notation. Dotted decimal or hexadecimal format is not allowed. Here are examples:
    • 10.11.144.0/24 10.11.144.0/255.255.255.0
    • 10.11.144.0/0xFFFFFF00
    • 0x0A0B9000/24
    • 0x0A0B9000/0xFFFFFF00

Quick ranges

Quick ranges allow administrators to define IP addresses to scan in a single comma-delimited string without creating separate records. You can enter IP addresses in one of the following formats.
  • An IP range defined by a slash and the number of bits in the subnetwork. For example, the string 10.10.10.0/24 scans 24 bits of IP addresses from 10.10.10.0 to 10.10.10.254.
  • An IP range defined by a dash. For example, the string 10.10.11.0-10.10.11.165 scans the IP addresses from 10.10.11.0 to 10.10.11.165.
  • A comma-separated list of specific IP addresses. For example the string 10.10.11.200,10.10.11.235 scans the IP addresses 10.10.11.200 and 10.10.11.235.
To create quick ranges:
  1. Click the Quick Ranges related link on the Discovery Schedule form.
  2. Enter the IP networks, IP ranges, and specific IP addresses to scan.
  3. Click Make Ranges.
Note: The Quick Range interface is for entering IP addresses only and cannot be used to edit IP addresses that have already been submitted.
Figure 1. Discovery Quick Ranges
The instance automatically displays the entries in the proper format. To make any changes to IP address ranges, select the IP address records.
Figure 2. Discovery Quick Ranges 2

Discover Now

Discover Now allows you to manually run a Discovery schedule. Manually running a schedule record does not affect the schedule. It continues to run as configured, despite manual execution.
  1. Navigate to Discovery > Discovery Schedules.
  2. Select the schedule you want to manually run.
  3. From Related links, click Discover now.