Zone transfer (AXFR/IXFR) Azure DNS
Migrate DNS from Zone transfer to Azure DNS.
9 record types move as they are. 2 things work differently at Azure DNS, and the preview shows exactly which of your records they affect.
Free preview. Read-only. Nothing changes until you apply.
Zone transfer to Azure DNS DNS migration differences
Generated from the same provider capability data the migration engine uses.
Moves as-is
- A
- AAAA
- CNAME
- MX
- TXT
- NS
- SRV
- CAA
- PTR
DS, TLSA, SSHFP, NAPTR, URI, DNAME, OPENPGPKEY, SMIMEA, DHCID, RP, HTTPS, SVCB aren't available
TTLs below 1s are raised
A typical Zone transfer zone at Azure DNS
Example records for example.com. Open any flagged row to read why it changed.
Zone transfer Azure DNS
- ExactA@
192.0.2.70
- ExactAAAA@
2001:db8::70
- 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.
- ExactCNAMEwww
example.com.
| Status | Type | Name | At Azure DNS | TTL | Details |
|---|---|---|---|---|---|
| Exact | A | @ |
| 5m | |
| Exact | AAAA | @ |
| 5m | |
| Exact | MX | @ |
| 1h | |
| Exact | TXT | @ |
| 1h | |
| Exact | CAA | @ |
| 1h | |
| Exact | TXT | _dmarc |
| 1h | |
| Exact | SRV | _sip._tls |
| 1h | |
| Exact | CNAME | www |
| 1h |
Set up the connections
Use the provider-specific credential guides before you preview, then keep the migration checklist beside the cutover plan.
How the move works
- 1
Connect Zone transfer
Connect Zone transfer with read-only access (Primary server(s) that allow zone transfers to our egress IP, optionally with a TSIG key).
- 2
Connect Azure DNS
Connect Azure DNS (Service principal (client ID + secret)). Write access is only used when you apply.
- 3
Review the preview
Check every record marked Review or Unsupported. Each one explains what changes and why.
- 4
Apply to Azure DNS
We snapshot the Azure DNS zone, write in batches, and leave Zone transfer untouched.
- 5
Verify
We query Azure DNS's own nameservers for every record and compare the answers before you switch.
- 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 Zone transfer
- Read-only source: zone transfer connections can be migrated from, monitored and backed up, but never written to.
- We reach primaries only over TCP port 53 at public addresses; private, loopback, link-local and metadata addresses are refused.
- A transfer shows what the server publishes: proxied (CDN) addresses, flattened apex CNAMEs and provider-managed records can't be recovered from it.
- DNSSEC signatures and keys (RRSIG, NSEC/NSEC3, DNSKEY, CDS/CDNSKEY) are dropped; the destination signs the zone itself.
- We can't receive NOTIFY messages, so changes are picked up by polling the SOA serial, then IXFR when the server supports it.
Access we need: Read-only: the primary must allow AXFR (and ideally IXFR) to our egress IP, optionally restricted to a TSIG key. Nothing is ever written back.
Good to know about Azure DNS
- Azure alias records point at Azure resource IDs, which don't exist outside Azure.
- Apex CNAMEs are not allowed. Use an alias record to an Azure resource or A/AAAA records.
Access we need: Reader on the DNS zone for the preview, DNS Zone Contributor to apply.
Questions
Will there be downtime moving from Zone transfer to Azure DNS?
Not if both providers serve the same answers during the switch. The records are copied to Azure DNS 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 Zone transfer?
No. We never write to Zone transfer. 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 Azure DNS and publish its new DS record. The cutover plan walks you through each step.
Ready to see your own zone?