By default, the high-security IP Service provides CNAME automatic scheduling without additional opening.

CNAME Auto Switch provides the failover capability that when an ISP line of an Anti-DDoS Pro instance encounters a problem, the service can be automatically switched to a healthy line, ensuring the service continuity and availability. For example, you enable CNAME Auto Switch for a domain protected by an Anti-DDoS Pro instance that has China Telecom and China Unicom two lines.

For example, you enable CNAME Auto Switch for a domain protected by an Anti-DDoS Pro instance that has China Telecom and China Unicom two lines.
  • When the IP address of the China Telecom line fails, the Anti-DDoS Pro service can automatically switch to the IP address of the China Unicom line that works normally.
  • When both IP addresses of the China Telecom line and the China Unicom line fail, CNAME Auto Switch cannot work.
Note Assume that you enable CNAME Auto Switch. When an IP address fails or is thrown into a black hole, the auto switch can be completed within one minute. The same CNAME is resolved to another healthy IP address on the DNS server. However, the actual time required for the changes to come into effect on the client depends on local DNS caching and updating.