When multiple authoritative name servers are configured for a domain at the registrar, DNS queries are distributed across all listed name servers in a round robin manner.
There is no configuration option to designate one authoritative name server as a backup that is only used when another name server is unavailable.
Important Notes
- All listed authoritative name servers are treated as active and equal.
- Queries may be sent to any of the configured name servers at any time.
- Authoritative DNS does not support active or passive failover at the registrar level.