RFC 2136 dynamic DNS (AXFR + DDNS) Azure DNS
Migrate DNS from AXFR/DDNS 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.
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, TLSA, SSHFP, NAPTR, URI, DNAME, OPENPGPKEY, SMIMEA, DHCID, RP, HTTPS, SVCB aren't available
TTLs below 1s are raised
A typical AXFR/DDNS zone at Azure DNS
Example records for example.com. Open any flagged row to read why it changed.
AXFR/DDNS 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 |
How the move works
- 1
Connect AXFR/DDNS
Connect AXFR/DDNS with read-only access (Primary server + TSIG key (HMAC-SHA256/512; SHA1/MD5 for legacy servers)).
- 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 AXFR/DDNS 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 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.
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 AXFR/DDNS 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 AXFR/DDNS?
No. We never write to AXFR/DDNS. 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?
Start a free preview