This article explains how to configure zone transfer when UltraDNS is set up as a secondary DNS provider and another DNS provider is acting as the primary.
Proper configuration ensures that UltraDNS can successfully retrieve zone data through AXFR and remain synchronized with the primary DNS server.
When to Use This Article
- You are configuring UltraDNS as a secondary DNS provider.
- Your primary DNS provider is hosted externally.
- Zone transfers to UltraDNS are failing or not updating.
How Zone Transfer Works in This Configuration
In a secondary configuration, UltraDNS retrieves DNS records from the primary DNS provider using AXFR.
The primary DNS server must allow zone transfers from UltraDNS IP addresses and send NOTIFY messages to UltraDNS when changes occur.
If the primary server does not permit AXFR or NOTIFY from UltraDNS, the zone will not update correctly.
How to Configure Zone Transfer
- Log in to the UltraDNS portal.
- Add the domain as a secondary domain.
- Enter the primary name server hostname or IP address.
- Ensure that UltraDNS AXFR IP addresses are whitelisted on the primary DNS provider.
- Save the configuration.
Verification
After saving the configuration, confirm that the secondary domain populates with DNS records in the UltraDNS portal.
If records do not appear or updates fail, verify that all required UltraDNS IP addresses are properly whitelisted and that firewall rules permit TCP port 53.
Important Notes
- All published UltraDNS transfer IP addresses must be allowed on the primary DNS server.
- NOTIFY must be enabled so UltraDNS can detect changes promptly.