Second Freq. Limit

Compared to Regional Frequency Settings, Second-Level Frequency Settings allow for more granular control over CC attacks measured in seconds.

How to Set Up Second Freq. Limit ?

• Sites → Sites Settings → Firewall → Second Freq. Limit → Create

  

Second Freq. Limit Field Descriptions

• URL: The domain you want to limit. Use .* if you want to apply to the entire site.

• Number of Requests: The allowed number of concurrent connections from the same IP within one second.

• Burst: If the number of connections from the same IP within one second exceeds the set number of requests, this field will limit the access speed.

• Protect Mode:

  • If the access frequency from the same IP in one second exceeds both the number of requests and the burst value, blocking will occur:

    • DENY: Rejects the IP connection, responding with HTTP status code 929.

    • DROP: Drops packets from the source IP that triggers the frequency limit, showing an ERR_CONNECTION_RESET error.

    • DROP + Blacklist: Drops packets and adds the source IP to a blacklist, which can be checked in Firewall > Block List.

• Block Duration: Measured in seconds, e.g., 300 means 5 minutes.

  

Blocking Example:

• Under normal conditions without restrictions, the connection rate would be:

  

• For the test domain, set the number of requests to 5 and the burst number to 2. If these limits are exceeded, the response will be DENY.

  

• At this point, you would observe that the response time per second is longer than the original response time.

  

• Open an additional terminal for testing to check if there's blocking after exceeding the limit: