Is there any rate-limiting for DNS queries?


I’m developing a TLD domain statistics project.
In this project, I’m making DNS queries for each .com, .net domain names. Not just A or NS records, MX, TXT, A record of MX.
Basicaly there are 143.228.571 “.com” domains today and I need to make 5 DNS queries for each domain. That makes more than 716 million queries for .com domain only.

3 day in a row, responded me so well and I never had trouble to get replies.
But now, it seems like CloudFlare has dropped my /24 subnet for DNS queries.

I’m able to get responses from my other subnets but not the subnet that I made the queries at the first place.

I saw a reply from a member of CloudFlare in other topic:

That was the main reason that I used in my project.

So, I need to be sure, is there a rate limiting or should I need to check my peers if there is an issue with the network.


That comment was regarding ten queries a second. In your case it would be rather 8000 queries a second (over 24 hours), which is somewhat of a difference and I wouldnt be surprised if Cloudflare actually recognised that as a form of attack.

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Is 8000 qps limit based on a single /32 or includes the /24?

I am not saying there is such a limit, just that this is a rather high number of requests, which I could easily imagine to be throttled. As for whether that applies only to individual addresses or entire blocks, that would be something best to clarify with support, as well as whether there is a limit overall.

The issue actually sounds the same as Throttling or other issue.