---
title: Registered Domain
description: The registered_domain processor reads a field containing a hostname and then writes the "registered domain" contained in the hostname to the target field...
url: https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/5399/reference/fleet/registered_domain-processor
products:
  - Elastic Agent
  - Fleet
applies_to:
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
---

# 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`). Optionally, the processor can store the rest of the domain, the `subdomain`, into another target field.
This processor uses the Mozilla Public Suffix list to determine the value.

## Example

```yaml
  - registered_domain:
      field: dns.question.name
      target_field: dns.question.registered_domain
      target_etld_field: dns.question.top_level_domain
      target_subdomain_field: dns.question.subdomain
      ignore_missing: true
      ignore_failure: true
```


## Configuration settings

<note>
  Elastic Agent processors execute *before* ingest pipelines, which means that your processor configurations cannot refer to fields that are created by ingest pipelines or Logstash. For more limitations, refer to [What are some limitations of using processors?](/elastic/docs-content/pull/5399/reference/fleet/agent-processors#limitations)
</note>


| 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.                 |
| `target_etld_field`      | No       |         | Target field for the effective top-level domain value.        |
| `target_subdomain_field` | No       |         | Target subdomain field for the subdomain value.               |
| `ignore_missing`         | No       | `false` | Whether to ignore errors when the source field is missing.    |
| `ignore_failure`         | No       | `false` | Whether to ignore all errors produced by the processor.       |
| `id`                     | No       |         | Identifier for this processor instance. Useful for debugging. |