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Alibaba Cloud DNS:Secondary DNS

Last Updated:Jul 05, 2025

If you want your DNS service to have higher disaster recovery capabilities, you can configure Secondary DNS.

What is Secondary DNS

Secondary DNS is a DNS disaster recovery backup service provided by Cloud DNS for users who use self-built DNS or third-party DNS. When Secondary DNS is enabled for a domain, the currently used DNS is called the primary DNS, and Cloud DNS becomes the secondary DNS by default. We establish a zone data transfer mechanism between the primary DNS and secondary DNS based on RFC standard protocols. When the primary DNS fails or experiences service interruption, the secondary DNS can continue to provide parsing services, ensuring the stable operation of your business globally.

Benefits

  • Disaster recovery backup, reducing the risk of business interruption

    When the primary DNS system fails, Secondary DNS can continue to provide domain name resolution services, ensuring business availability.

  • Stable and reliable, ensuring stable business operation

    Cloud DNS provides 100% SLA service, with global DNS clusters backing up each other, ensuring the service never goes down.

  • Global nodes, improving domain name resolution efficiency

    Nodes are distributed globally, and continuously expanding data centers provide smoother cross-domain experiences.

  • Load balancing, distributing traffic to reduce load

    When Secondary DNS and primary DNS provide resolution services simultaneously, traffic load balancing can be achieved.

  • Security protection, real-time attack detection, global 10T+ bandwidth reserve

    When you choose to hide the primary DNS and have the secondary DNS (Cloud DNS) provide resolution services externally, you can better protect the security of the primary DNS.