---
title: Access Control Lists (ACLs) · Cloudflare DNS docs
description: Access Control Lists (ACLs) define allowed source IP addresses from where servers accept incoming data or control messages.
lastUpdated: 2024-09-20T08:42:16.000Z
source_url:
  html: https://72906cb7.preview.developers.cloudflare.com/dns/zone-setups/zone-transfers/access-control-lists/index.md
  md: https://72906cb7.preview.developers.cloudflare.com/dns/zone-setups/zone-transfers/access-control-lists/
---

Access Control Lists (ACLs) define allowed source IP addresses from where servers accept incoming data or control messages.

When setting up new DNS zone transfers ([incoming](https://developers.cloudflare.com/dns/zone-setups/zone-transfers/cloudflare-as-secondary/) or [outgoing](https://developers.cloudflare.com/dns/zone-setups/zone-transfers/cloudflare-as-primary/)), you will need to update the ACL at your other DNS provider(s) to allow Cloudflare to communicate with their server(s). You can find the Cloudflare IP addresses you need to allow at your other DNS provider(s) at [Cloudflare IP addresses](https://developers.cloudflare.com/dns/zone-setups/zone-transfers/access-control-lists/cloudflare-ip-addresses/).

You need to [create a new ACL](https://developers.cloudflare.com/dns/zone-setups/zone-transfers/access-control-lists/create-new-list/) in your Cloudflare account in the following situations if you want to specify additional NOTIFY IPs that Cloudflare should listen to (Cloudflare as secondary) or additional IPs Cloudflare should accept zone transfer requests from (Cloudflare as primary).
