You can use network acceleration for service interaction between an Anti-DDoS Premium Insurance or Unlimited instance and an Anti-DDoS Premium MCA instance. If no attacks occur, service traffic is sent to the IP address of the MCA instance for acceleration. If attacks occur, service traffic is automatically switched to the Anti-DDoS Premium Insurance or Unlimited instance for scrubbing. Normal traffic is then forwarded to the origin server.
Prerequisites
- An Anti-DDoS Premium MCA instance is purchased. For more information, see Purchase an MCA plan for an Anti-DDoS Premium instance.
- An Anti-DDoS Premium Insurance or Unlimited instance is purchased, and your service is added to the Anti-DDoS Premium Insurance
or Unlimited instance. For more information, see Purchase an insurance plan or unlimited plan for an Anti-DDoS Premium instance and Add a website (website service) and Create forwarding rules (non-website service).
Notice The bandwidth and QPS of the Anti-DDoS Premium Insurance or Unlimited instance must meet protection requirements of your service. This ensures that the instance can process service traffic after the traffic is switched to the Anti-DDoS Premium Insurance or Unlimited instance.
- The Anti-DDoS Premium Insurance or Unlimited instance can forward traffic as expected. For more information, see Verify the forwarding configuration on your local machine.
Background information
If you add your service to only an Anti-DDoS Premium Insurance or Unlimited instance,
users in mainland China will experience increased latency. You can purchase both an
Anti-DDoS Premium Insurance or Unlimited instance and an Anti-DDoS Premium MCA instance.
This allows you to accelerate user access by using the MCA instance if no attacks
occur. If your service encounters attacks, service traffic is forwarded to the Anti-DDoS
Premium Insurance or Unlimited instance for protection. The following figure shows
the interaction process.

For more information, see Configure Anti-DDoS Premium MCA.
Procedure
What to do next
- Switch traffic back: Assume that the general interaction rule takes effect and service
traffic is switched to Anti-DDoS Pro or Anti-DDoS Premium. If the waiting time of switching back has not arrived, you can click Switch back to manually switch the traffic back to the cloud resource.
Note The Switch back button appears only when service traffic is switched to Anti-DDoS or Anti-DDoS Premium and the waiting time of switching back does not arrive.The following exceptions may occur when you perform this operation:
- If all cloud resources are in blackhole filtering, the operation fails.
- If some cloud resources are in blackhole filtering and some are normal, traffic is switched to the normal cloud resources. After blackhole filtering is deactivated, traffic is automatically switched to other cloud resources.
- Edit an interaction rule: On the General tab, find the rule that you want to edit and click Edit in the Actions column. You can modify parameters except Interaction Scenario and Name.
- Delete an interaction rule: On the General tab, find the rule that you want to delete and click Delete in the Actions column.
Warning Before you delete an interaction rule, make sure that the service traffic is no longer directed to the CNAME address assigned by Sec-Traffic Manager. Otherwise, your service becomes unavailable after you delete the rule.