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Comment by dknecht

5 years ago

Cloudflare has worked providers to make sure they can efficiently route. If you find case where this isn’t the case please let us know.

Cloudflare DNS does not route efficiently with AWS CloudFront anycast DNS. I tracked down insanely slow `rustup update` downloads to incorrect selection of ideal routes to the AWS resources caused by using CF to resolve the DNS. Switching to a different resolver that works with anycast and EDNS fixed it.

CF saying “we break standard DNS geo routing but work with providers to route things right” isn’t very inspiring.

  • > Cloudflare DNS does not route efficiently with AWS CloudFront anycast DNS. I tracked down insanely slow `rustup update` downloads to incorrect selection of ideal routes to the AWS resources caused by using CF to resolve the DNS.

    Please send me details (silverlock at cloudflare) here - AWS has our geofeed.

    If you can include resolution details - e.g. dig @1.1.1.1 <cloudfront-host> +nsid - with the incorrect CF results, we can provide them to AWS.

    Folks did geo-routing with DNS long before ECS was included, and there’s a privacy trade-off to be had. We’re exploring ways to make this better but there is no free lunch.

    • Thanks for providing your info. I stopped using CF for resolution because of this almost two years ago; I don’t have a reason to think the situation changed but if I get a chance I can try to reproduce it and get back to you.