This topic describes how to configure a cleaning threshold in the Anti-DDoS Basic
console.
Background information
Anti-DDoS Basic is applied to protect Alibaba Cloud assets by default. The service
is provided free of charge after each asset is activated. The assets include Elastic
Compute Service, Server Load Balancer, and Elastic IP Address instances. The maximum
throughput of DDoS attacks that an asset encounters may exceed the specified cleaning
threshold. In such cases, Anit-DDoS cleans attack traffic and performs other counter
measures to ensure business continuity.
Procedure
- Log on to the Alibaba Cloud Anti-DDoS Basic console.
- On the top of the Assets page, select a region.
- Select the ECS, SLB, EIP (including NAT), or Others tab based on the type of cloud service for which you want to configure a cleaning
threshold.
- In a list of instances, find the target instance and click the IP address of the instance.
If excessive instances exist, we recommend that you search for the target instance
by using the
instance ID,
instance name, or
instance IP as the search condition.

- In the Instances Details dialog box, click Cleaning Settings.

- In the Cleaning Settings dialog box, select Default or Manual Setting in the Cleaning Threshold field.
- Default: Anti-DDoS Basic dynamically adjusts the cleaning threshold based on the traffic
load of an asset.
- Manual setting: You can select a specific threshold that includes two values. One indicates the
minimum throughput and the other indicates the mininum packets per second (PPS).
Recommendations:
- Configure a cleaning threshold of which the value is slightly greater than the maximum
bandwidth for actual incoming requests. If the specified value of a threshold is greater
than expected, the effect of protection is compromised. If the specified value of
a threshold is less than expected, legitimate access may be affected when traffic
cleaning is triggered.
- If legitimate access is affected, we recommend that you increase the value of the
cleaning threshold.
- During large promotions or activities for a website, we recommend that you increase
the specified value of a cleaning threshold.

Result
The cleaning threshold is configured. When the maximum throughput of incoming requests
that a website can serve reaches the specified cleaning threshold, Anti-DDoS Basic
launches traffic cleaning.