> For the complete documentation index, see [llms.txt](https://docs.link11.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.link11.com/product-guides/secure-dns/introduction.md).

# Introduction

Link11 Secure DNS is an Anycast DNS service, which runs in all Link11 datacenters and provides DNS services to global clients.

Its highlights include:

* **Hardening** against DDoS, DNS poisoning, and other threats.
* **Globally distributed PoPs**, each with redundant services and failover.
* **Auto-routing** of client requests to the closest Link11 datacenter, to minimize response time.
* **Secure API access**.
* **Integration with Let's Encrypt**, and enabling TSL certificate auto-renewal for other Link11 services.

{% hint style="info" %}
If a Link11 customer wants to use [Let's Encrypt](https://letsencrypt.org/) and auto-renew the various Link11 services' TLS certificates, then the system has to include and use Secure DNS.
{% endhint %}