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dnsmigrator

Google Cloud DNS RFC 2136 dynamic DNS (AXFR + DDNS)

Migrate DNS from Cloud DNS to AXFR/DDNS.

16 record types move as they are. 1 things work differently at AXFR/DDNS, and the preview shows exactly which of your records they affect.

Free preview. Read-only. Nothing changes until you apply.

What works differently

Generated from the same provider capability data the migration engine uses.

Moves as-is

  • A
  • AAAA
  • CNAME
  • MX
  • TXT
  • NS
  • SRV
  • CAA
  • PTR
  • DS
  • HTTPS
  • SVCB
  • TLSA
  • SSHFP
  • NAPTR
  • SPF

Routing policies are flattened

AXFR/DDNS has no routing policies. Weighted, geo and latency sets collapse into one set of answers, and failover keeps only the primary. Each one is flagged for review.

A typical Cloud DNS zone at AXFR/DDNS

Example records for example.com. Open any flagged row to read why it changed.

Cloud DNS AXFR/DDNS

  • ExactA@

    192.0.2.40

  • ExactMX@

    10 mx1.mail.example.net. +1

  • ExactTXT@

    "v=spf1 include:_spf.example.net -all"

  • ExactCAA@

    0 issue "letsencrypt.org"

  • ExactTXT_dmarc

    "v=DMARC1; p=reject; rua=mailto:dmarc@example.com"

  • ExactSRV_sip._tls

    100 1 443 sip.example.net.

  • ReviewAeu

    192.0.2.41 +1

    Geo routing isn't available at the destination. All 2 answers are served together as simple round-robin.

  • ExactCNAMEwww

    example.com.

How the move works

  1. 1

    Connect Cloud DNS

    Connect Cloud DNS with read-only access (Service account key (JSON)).

  2. 2

    Connect AXFR/DDNS

    Connect AXFR/DDNS (Primary server + TSIG key (HMAC-SHA256/512; SHA1/MD5 for legacy servers)). Write access is only used when you apply.

  3. 3

    Review the preview

    Check every record marked Review or Unsupported. Each one explains what changes and why.

  4. 4

    Apply to AXFR/DDNS

    We snapshot the AXFR/DDNS zone, write in batches, and leave Cloud DNS untouched.

  5. 5

    Verify

    We query AXFR/DDNS's own nameservers for every record and compare the answers before you switch.

  6. 6

    Switch nameservers

    Lower TTLs a day or two ahead, remove any DS record if DNSSEC is on, then point the domain at the new nameservers at your registrar.

Good to know about Cloud DNS

  • Routing policies (weighted round robin, geolocation, failover) don't carry over to most providers.
  • Apex CNAMEs are not allowed.

Access we need: roles/dns.reader for the preview, roles/dns.admin to apply.

Good to know about AXFR/DDNS

  • We reach the primary only over TCP port 53 at a public address; servers on private networks must expose port 53 publicly and allow our egress IPs.
  • Zones can't be listed or created over DNS: list them in the connection and create them on the server first.
  • Records of types we can't encode (e.g. LOC, CERT) and DNSSEC records are skipped when reading; signing stays with the server.

Access we need: The TSIG key needs zone-transfer (AXFR) rights for the preview and an update-policy grant for the managed zones to apply.

Questions

Will there be downtime moving from Cloud DNS to AXFR/DDNS?

Not if both providers serve the same answers during the switch. The records are copied to AXFR/DDNS and verified before you change nameservers, so resolvers get the same answer from either side while caches expire.

Do I have to delete anything at Cloud DNS?

No. We never write to Cloud DNS. Keep the old zone for a week after cutover so you can switch back instantly if anything looks wrong.

What about DNSSEC?

If DNSSEC is on, remove the DS record at your registrar and wait for it to expire before switching nameservers. Then enable DNSSEC at AXFR/DDNS and publish its new DS record. The cutover plan walks you through each step.

Related migrations

Ready to see your own zone?

Start a free preview