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    Alibaba Cloud DNS:Implement dual-stack resolution and disaster recovery with GTM

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    Alibaba Cloud DNS:Implement dual-stack resolution and disaster recovery with GTM

    Last Updated:Jun 22, 2026

    Scenarios

    Your application is deployed across two sites, each with a public IPv4 and IPv6 address. When a site is healthy, clients can reach it over either address. If an IPv4 or IPv6 address becomes unhealthy, traffic automatically fails over to a healthy address of the same IP version.

    Note

    • An unhealthy IPv4 address can fail over only to another healthy IPv4 address. The same rule applies to IPv6 addresses.

    • An unhealthy IPv4 or IPv6 address cannot fail over to an address of a different IP version. This is because the record type is already specified in the DNS query from the client.

    Prerequisites

    • Your domain cloud-example.com is hosted on Alibaba Cloud DNS. The subdomain managed by GTM is www.cloud-example.com.

      Note

      If your domain uses a third-party DNS provider, add a CNAME record pointing to the GTM access zone name in that provider's console.

    • A GTM instance is available. If not, purchase a subscription instance.

    Expected outcome

    Expected failover behavior:

    Source of DNS query

    Application service address

    Failover address

    Global default (A record request)

    1.1.XX.XX

    2.2.XX.XX

    Global default (AAAA record request)

    240e:f7:7000:c2:3::1XX

    240e:f7:7000:c2:3::2XX

    Procedure

    Configure disaster recovery for IPv4 addresses

    1. Go to the Alibaba Cloud DNS - Global Traffic Manager console.

    2. On the Access Domain tab, click Create Access Domain.

    3. In the Select Scenario dialog box, select Primary/Secondary Disaster Recovery.

    4. On the Create Access Domain page, click the access zone name icon and select Basic Configuration.

      image

    5. After you configure the parameters on the Basic Configuration page, click Submit. For more information, see Configure an access domain name.

      Access Domain: The domain name of the service, such as www.cloud-example.com.

      For Record Type, select A. For Bind Instance, select your purchased GTM instance. For Record Type, select A -- IPv4 or domain-based scheduling. Set Global TTL to 30 seconds. The Status is disabled by default. We recommend enabling the access domain only after configuring the address pool, addresses, and load balancing policy.

    6. On the current page, click the address pool icon and select Basic Configuration.image

    7. On the Access Domain page, click the address icon and select Basic Configuration. Add the endpoint IP address, configure a health check template (for this example, TCP protocol, port 80), and create the address. Repeat for all required addresses.

      Note

      If no health check template exists, click Add Health Check Template. Health check templates.

      Important

      If you encounter red or orange alerts during setup, check the health status of your addresses.

    8. The scenario template generates a load balancing policy. Manual configuration is typically not needed.

      Important

      With one-way data synchronization (from primary to standby), data generated on the standby during a failover cannot be returned to the primary. To prevent data loss upon recovery, set the address pool's load balancing policy to Non-Preemptive Mode. Configure an address pool.

    Configure disaster recovery for IPv6 addresses

    1. Go to the Alibaba Cloud DNS - Global Traffic Manager console.

    2. On the Access Domain tab, click Create Access Domain.

    3. In the Select Scenario dialog box, select Primary/Secondary Disaster Recovery.

    4. On the Create Access Domain page, click the access zone name icon and select Basic Configuration.

      image

    5. Complete the parameter settings on the page and then click Submit. For more information, see Access domain name configuration.

      Access Domain: The domain name that is used for access, such as www.cloud-example.com. The access domain name must match the domain name in the A record.

      Record Type: Select AAAA.

      Important

      • If the access domain name already has an attached instance, the Bind Instance drop-down list displays the The current access domain name is bound to an instance, and the instance can be reused. option. You can select this option to reuse the instance.

      • For a single domain name, you can enable instances if you set the Record Type to both A and AAAA. However, setting the Record Type to A and CNAME or AAAA and CNAME causes a conflict and prevents the instances from being enabled.

      Set Global TTL (Seconds) to 30. The Status is disabled by default. We recommend enabling the access domain only after you have configured the address pool, addresses, and load balancing policy.

    6. Follow the procedure for configuring disaster recovery for IPv4 addresses to configure the IPv6 address pool, addresses, and health checks.

      Important

      If the monitored object is an IPv6 address, set Type to IPv6 when you create a monitoring template.

      image

    7. Configure monitoring and alerting for the instance. For more information, see Alert configuration.

    8. On the Access Domain page, click the icon for the access domain and select Enable.

    9. In the confirmation dialog box, verify the details and click OK to enable the Access Domain.

      Important

      • If a DNS record with the same name and type already exists in Alibaba Cloud DNS, GTM policies take precedence over standard DNS resolution for that domain.

      • If the GTM instance is disabled or deleted, DNS queries fall back to Alibaba Cloud DNS Public Zone records.