> For the complete documentation index, see [llms.txt](https://docs.ionos.com/cloud/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ionos.com/cloud/network-services/cloud-dns/dcd-how-tos/public-zone/secondary-zone/start-zone-transfer.md).
# Start Zone Transfer
A zone transfer is a fundamental process for replicating DNS records from a primary DNS server to one or more secondary servers. This process ensures redundancy, enhances fault tolerance, and improves DNS resolution performance across distributed networks.
Creating a zone transfer from a primary to a secondary zone involves configuring authoritative DNS servers to synchronize zone data securely. The primary server maintains the original zone file; the secondary servers obtain and periodically update their copies through the standard [AXFR](https://docs.ionos.com/cloud/support/general-information/glossary-of-terms#authoritative-zone-transfer-axfr) zone transfer protocol.
{% hint style="info" %}
**Prerequisites:**
* Cloud DNS relies on the following Anycast addresses to send DNS notification messages. Ensure you whitelist the following IP addresses:
* **IPv4:** `212.227.123.25`
* **IPv6:** `2001:8d8:fe:53::5cd:25`
* Ensure that port 53 is open for both TCP and UDP connections.
{% endhint %}
To begin zone transfer, follow these steps:
1\. In the **DCD**, go to **Menu** > **Network Services** > **Cloud DNS** > **Public zones** tab.
2\. Select **Secondary Zones** from the drop-down list.
{% hint style="info" %}
**Info:** The **Public zones** section displays the zones if you have already created them. Select **Show secondary zones** to view secondary zones. This option only appears if you have created secondary zones but have not configured primary zones.
{% endhint %}
3\. Select the zone to initiate the transfer process.
4\. Select **Start zone transfer**.
Alternatively, you can begin zone transfer using the **Start zone transfer** option in either the [ACTIONS](/cloud/network-services/cloud-dns/dcd-how-tos/public-zone/secondary-zone/view-secondary-zones.md) column or the [Details & Records](/cloud/network-services/cloud-dns/dcd-how-tos/public-zone/secondary-zone/view-secondary-zone-details.md) window.
5\. Select **Start transfer** in the **Start zone transfer** view to begin the process.
{% hint style="success" %}
**Result:** The zone transfer process has begun.
{% endhint %}
---
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