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Anti-DDoS:Change the CNAME record to redirect traffic to Sec-Traffic Manager

Last Updated:Mar 02, 2026

After you create a scheduling rule in Sec-Traffic Manager, update the CNAME record of your domain name to route inbound traffic through Sec-Traffic Manager. The scheduling rule does not take effect until the CNAME record is updated.

Prerequisites

  • A scheduling rule configured in Sec-Traffic Manager. For more information, see Overview

How CNAME-based traffic redirection works

When you add a scheduling rule, Sec-Traffic Manager generates a CNAME. To route inbound traffic through Sec-Traffic Manager, map your domain name to this CNAME by updating the DNS record.

The following example uses Alibaba Cloud DNS with the domain name aliyundoc.com. If your domain is hosted on a third-party DNS service, use these steps as a reference.

The result is a DNS record that looks like this:

aliyundoc.com  CNAME  <CNAME assigned by Sec-Traffic Manager>

Find the CNAME assigned by Sec-Traffic Manager

  1. Log on to the Anti-DDoS Pro console.

  2. In the left-side navigation pane, choose Provisioning > Sec-Traffic Manager.

  3. Find the scheduling rule for your domain name and note the CNAME assigned by Sec-Traffic Manager.

Update the DNS record

  1. Log on to the Alibaba Cloud DNS console.

  2. In the left-side navigation pane, choose Configurations > Public Zone. Find your domain name and click DNS Settings in the Actions column.

  3. On the DNS Settings page, find the existing DNS record for your domain name and click Modify in the Actions column.

    Note: If no existing DNS record matches, click Add DNS Record to create a new record instead.

  4. In the Edit Record or Add Record panel, configure the following fields:

    FieldValue
    Record TypeCNAME
    Record ValueThe CNAME from Sec-Traffic Manager
  5. Click OK and wait for the DNS changes to propagate.

Verify the configuration

  1. Open a browser and access your website to confirm that it loads correctly.

  2. If the website is inaccessible or responds slowly, see How do I handle the issues of slow response, high latency, and access failure on my service that is protected by an Anti-DDoS Pro or Anti-DDoS Premium instance?