[[processor-registered-domain]]
=== Registered Domain

The `registered_domain` processor reads a field containing a hostname and then
writes the "registered domain" contained in the hostname to the target field.
For example, given `www.google.co.uk` the processor would output `google.co.uk`.
In other words the "registered domain" is the effective top-level domain
(`co.uk`) plus one level (`google`).

This processor uses the Mozilla Public Suffix list to determine the value.

[source,yaml]
----
processors:
- registered_domain:
    field: dns.question.name
    target_field: dns.question.registered_domain
    ignore_missing: true
    ignore_failure: true
----

The `registered_domain` processor has the following configuration settings:

.Registered Domain options
[options="header"]
|======
| Name             | Required | Default    | Description                                                      |
| `field`          | yes      |            | Source field containing a fully qualified domain name (FQDN).    |
| `target_field`   | yes      |            | Target field for the registered domain value.                    |
| `ignore_missing` | no       | false      | Ignore errors when the source field is missing.                  |
| `ignore_failure` | no       | false      | Ignore all errors produced by the processor.                     |
| `id`             | no       |            | An identifier for this processor instance. Useful for debugging. |
|======
