# Required Network Hostname Access

Learn which hostnames you must allow access to for FusionAuth to work.

> For the index of this section of the site, see [llms.txt](https://fusionauth.io/docs/llms.txt)

If you have a FusionAuth instance with a license, you must allow access to the following hostnames.

*   `https://reactor.fusionauth.io`
*   `https://metrics.fusionauth.io`
*   `https://license.fusionauth.io`

Learn more about [network requirements](https://fusionauth.io/docs/deploy/production/system-requirements.md#network-access) for running FusionAuth.
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## Other pages in Harden

> For the full index of this section, see [Deploy](https://fusionauth.io/docs/llms-deploy.txt).

- [Harden a FusionAuth Production Instance](https://fusionauth.io/docs/deploy/harden/harden-a-production-instance.md): Learn which settings to change to secure a FusionAuth instance before it goes into production.
- [Secure a FusionAuth Instance](https://fusionauth.io/docs/deploy/harden.md): Learn how to secure the network, database, and configuration of a self-hosted FusionAuth instance.
- [Networking Configuration](https://fusionauth.io/docs/deploy/harden/networking.md): Learn about FusionAuth networking configuration, especially IP resolution.