Alibaba Cloud DNS has a free edition and three paid editions. The following table describes the differences between the editions.
|Feature/Edition||Free Edition||Personal Edition||Enterprise Standard Edition||Enterprise Ultimate Edition|
|Applicable websites||Personal homepage and space||Individual users and small and micro enterprises that do not have any special requirements for the DNS resolution speed, effective time, or stability||Medium- and large-sized enterprise websites or services that have higher requirements on the DNS resolution speed, effective time, Service Level Agreement (SLA), and intelligent DNS resolution||Internet technology companies, financial institutions, and multinational groups that have highest requirements for the DNS resolution speed, effective time, and customization|
|SLA||N/A||100% monthly availability||100% monthly availability||100% monthly availability|
|DNS nodes||4 in China||9 in China and 11 outside China||9 in China and 11 outside China||9 in China and 11 outside China|
|★Subdomain hierarchical authorization||Supported||Supported||Supported||Supported|
|Number of subdomains||Unlimited||Unlimited||Unlimited||Unlimited|
|Number of subdomain levels||5||20||20||20|
|Minimum TTL (second)||600||600||60||1|
|Intelligent DNS resolution||China Unicom, China Telecom, China Mobile, CERNET, and outside China||China Unicom, China Telecom, China Mobile, Dr. Peng Telecom & Media Group, CERNET, China Broadcasting Network, and outside China||Aliyun, Provincial branches of China Unicom, China Telecom, China Mobile, Dr. Peng Telecom & Media Group, CERNET, and China Broadcasting Network, outside China (continents, countries, or regions)||All fixed intelligent DNS resolution lines included and custom IP range resolution supported|
|Number of URL forwarding records||2||5||10||10|
|Weight configuration (A, CNAME, and AAAA records)||Supported||Supported||Supported||Supported|
|IP addresses that are used for load balancing in a single line of a domain name||10||90||90||90|
|★Statistics on the number of requests (accurate to the subdomain level)||Not supported||Supported||Supported||Supported|
|★DNS over IPv6||Supported||Supported||Supported||Supported|
|Secondary DNS||Not supported||Not supported||Not supported||Supported|
|DNS data backup||Not supported||Not supported||Supported (backup by day)||Supported (backup by hour)|
|Custom NS name (to be provided)||Not supported||N/A||N/A||N/A|
The free edition of Alibaba Cloud DNS does not support DNS protection. The following table describes the protection level in the paid editions.
|Protection level||DNS Attack Defense Basic||DNS Attack Defense Advanced|
|Service scope||Provides basic protection against DNS attacks for domain names bound to Alibaba Cloud DNS instances. This level provides protection for a maximum of 10 million queries per second (QPS) for each domain name.||Provides comprehensive protection against DNS attacks for domain names bound to Alibaba Cloud DNS instances. This level provides protection for over 100 million QPS for each domain name to ensure normal DNS resolution under volumetric DDoS attacks.|
By default, each Alibaba Cloud DNS instance that you purchase supports one domain name, such as example.com. If you want an instance to support multiple domain names, such as example.cn and example.net, you can increase the number of domain names.