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Convert partial setup to secondary setup

If you initially set up a partial zone on Cloudflare, you can later convert it to use a secondary setup.

Footnotes

  1. Meaning you have one or more subdomains (sub.example.com) added to Cloudflare as their own zone, separate from your apex domain (example.com).

This page will guide you through this conversion using export and import and API calls.

Before you begin

Make sure you consider the following:

1. Prepare a zone file

  1. Export a zone file from the authoritative DNS provider you were using with your partial (CNAME) setup.
  2. Edit the zone file to remove any occurrences of the cdn.cloudflare.net suffix.
  • If the CNAME target is only appending the Cloudflare suffix to the same hostname at which it is created, replace it by the records on the Cloudflare partial zone.

Example

Original record in authoritative DNS provider:

TypeNameContent
CNAMEwww.example.comwww.example.com.cdn.cloudflare.net

Records in the Cloudflare partial zone:

TypeNameContent
Awww.example.com<IPv4>
Awww.example.com<IPv4>

Final records adjusted in the zone file:

TypeNameContent
Awww.example.com<IPv4>
Awww.example.com<IPv4>
  • If the CNAME record points to a different hostname, keep this record but remove the cdn.cloudflare.net suffix, and also bring the records from the Cloudflare partial zone.

Example

Original record in authoritative DNS provider:

TypeNameContent
CNAMEwww.example.comother-hostname.example.com.cdn.cloudflare.net

Records in the Cloudflare partial zone:

TypeNameContent
Aother-hostname.example.com<IPv4>
Aother-hostname.example.com<IPv4>

Final records adjusted in the zone file:

TypeNameContent
CNAMEwww.example.comother-hostname.example.com
Aother-hostname.example.com<IPv4>
Aother-hostname.example.com<IPv4>

2. Configure the Cloudflare zone

  1. Use the Import DNS Records endpoint with a properly formatted zone file to import the records into your partial zone.

    The zone file size limit is 256 KiB (262144 bytes).

    Existing and already proxied records will not be overwritten by the import.

  2. Use the Update DNS Settings endpoint with secondary_overrides set to true, to enable Secondary DNS Override.

  1. Use the Edit Zone endpoint with type set to secondary, to convert the zone type.

    You can verify if it answers as expected by querying the new assigned secondary nameservers. You can find your nameservers in DNS > Records, and they should follow a format like ns0123.secondary.cloudflare.com.

Terminal window
# Replace ns0123 with your actual Cloudflare nameservers
dig example.com @ns0123.secondary.cloudflare.com
  1. At your registrar, update your nameservers to point to the Cloudflare nameservers.

Once the time to live (TTL) of previous NS records is expired and this information is evicted from resolvers’ cache, your zone will be properly delegated to Cloudflare. In order to update DNS records, you must configure zone transfers in the next steps.

3. Configure the zone transfers

  1. Remove all references to cdn.cloudflare.net from your primary DNS provider. You can do this by importing the same zone file you prepared in Step 1 onto your primary zone.
  1. Enable outgoing zone transfers at your primary provider and create a peer DNS server on your Cloudflare account.

To create a peer server using the dashboard:

  1. Log in to the Cloudflare dashboard and select your account.
  2. Go to Manage Account > Configurations.
  3. Select DNS Zone Transfers.
  4. For Peer DNS servers, select Create.
  5. Enter the following information, paying particular attention to:
    • IP: Specifies where Cloudflare sends transfer requests to.
    • Port: Specifies the IP Port for the transfer IP.
    • Enable incremental (IXFR) zone transfers: Specifies if Cloudflare sends IXFR requests in addition to the default AXFR requests.
    • Link an existing TSIG: If desired, link the TSIG you previously created.
  6. Select Create.
  1. Link your Cloudflare zone to the peer DNS server you just created.
  1. Go to DNS > Records.
  2. Under DNS Zone Transfers, select Manage linked peers.
  3. Choose a value for Zone refresh, which controls the number of seconds between zone updates from your primary DNS server.
  4. Select the peer server you previously created. If needed, you can link more than one peer server to a zone.
  5. Select Save to confirm.
  1. In DNS > Settings, confirm the linked peer is listed under DNS Zone Transfers, and select Initiate zone transfer. Alternatively, you can use the Force AXFR endpoint.