Create a Discovery legacy identifier

If your system is configured to use legacy identifiers, you can create new identifiers to examine the attributes from specific tables that extend tables in the default Discovery rules.

About this task

The default identifiers provided with Discovery should be adequate for most discoveries. However, if you need to discover data from a child table, such as Linux Server [cmdb_ci_linux_server], you can create a custom legacy identifier and select the exact criteria you want to add to the CMDB.


  1. Navigate to Discovery Definition > CI Identification > Identifiers.
  2. Click New.
  3. Fill out the unique fields provided by the identifier form.
    Table 1. Identifier form fields
    Field Input Fields
    Applies to Select the ServiceNow table of the device class for this identifier. For example, if the class is Printer, then the table is cmdb_ci_printer.
    Order Configure the order in which the identification criteria are evaluated. An example might be serial number - 910, network name - 920, and computer name - 930.
    Script Create the conditions that determine what Discovery should do when the results are returned from a search of the CMDB for this identifier. For example, you might want to stop Discovery if two or more CIs in the CMDB match this identifier. Or you might want to evaluate additional identifiers even after a match has been established with this identifier. Use the scripting methods described below to tell Discovery how to respond.

    The completed Discovery identifier form looks like this:

    Figure 1. Discovery identifier form