After you add a website to an Anti-DDoS Pro or Anti-DDoS Premium instance, you must modify the DNS records of the domain name for the website to reroute the traffic directed to your website to the instance. The instance scrubs the traffic and forwards normal traffic to the origin server. This topic describes how to modify the CNAME record of a domain name. In this example, the DNS resolution service is provided by Alibaba Cloud DNS.
Prerequisites
- A domain name is added to an Anti-DDoS Pro or Anti-DDoS Premium instance. For more information, see Step 1: Add forwarding rules.
- The back-to-origin IP addresses of the Anti-DDoS Pro or Anti-DDoS Premium instance are added to the whitelist of the origin server. If you deploy third-party security software, such as a firewall, on your origin server, add the back-to-origin IP addresses to the whitelist of the security software. For more information, see Allow back-to-origin IP addresses to access the origin server.
- The traffic forwarding settings are in effect. Before you switch service traffic to the Anti-DDoS Pro or Anti-DDoS Premium instance, we recommend that you use your local computer to verify that the instance can forward traffic to the origin server. For more information, see Verify the forwarding configuration on your local machine.
Warning If you switch your service traffic to the Anti-DDoS Pro or Anti-DDoS Premium instance before the forwarding settings take effect, your service may be interrupted.
Background information
In the following example, your domain name is hosted on Alibaba Cloud DNS.
If you use a third-party DNS service, log on to the system of the DNS provider to change the DNS records. The following example is only for reference.
Assume that you add the domain name bgp.ddostest.com to Anti-DDoS Pro or Anti-DDoS Premium. The following procedure describes how to change and add DNS records in the Alibaba Cloud DNS console.