N-central Help

Create a filter

Filters enable you to display groups of devices based on specific criteria including type of hardware, operating system and applications. You can use these filters on custom dashboards to monitor key devices, or use them to define rules or tasks.

When creating rules, you can use more than one filter. Multiple filters are linked by OR logic; devices that meet any of the filters used when configuring a rule will be included.

  1. Go to ConfigurationFilters and click Add.
  2. Enter a name and description.
  3. Select who can view and use the filter.
  4. Use the drop-down lists to build the filter criteria.
  5. Click Advanced Mode to develop more precise filtering. For more information, see Advanced variables and custom expressions below..
  6. Click Show Devices on the right-hand side of the screen and click Preview to see the results of the filter you are creating.

  7. Click Save.

The filter is added to the filters list and ready to use in SolarWinds N-central including in service templates, scheduled tasks, rules and Dashboards.

You can easily find the filter later using the filter search.

Advanced variables and custom expressions

In the Advanced Mode, you can define criteria relationships specifically to create extremely precise Filters. The default relationships are:

  • A and B - Both Criteria A and Criteria B must be met.
  • (A and B) or C - Either the combination of both Criteria A and Criteria B or just Criteria C must be met.
  • (A or B) and (C or D) - The combination of either Criteria A or Criteria B and the combination of either Criteria C or Criteria D must be met.
  • ((A or B) and (C or D)) or E - The combination of either Criteria A or Criteria B and the combination of either Criteria C or Criteria D or just Criteria E must be met.

You can define your own custom expression. Click Custom Expression from the Find devices where drop-down list box. You can use variables and relational operators based on:

  • Individual criteria must be identified with either an uppercase alphabetical character (A-Z), a lowercase alphabetical character (a-z) or a single-digit numerical value (0-9).
  • The only relational operators that are supported are AND and OR. AND identifies that the variables must be matched in combination while OR identifies that variables must be matched either in combination or individually.
  • Variables can be grouped in parentheses to isolate relationships from other variables or relationships.

For example, you can define the following custom expression (A and B) or (c and d) or (1 and 2).

After typing the custom expression into the field, click Generate to display the number of criteria parameters that are indicated in your expression. In the example provided above, six different criteria parameters would be needed (A, B, c, d, 1 and 2).