Non-optimal DNS resolution for Flickr uploader from Hong Kong


#1

I noticed my uploads to Flickr got slower since I changed my DNS entry to 1.1.1.1 on my home network.

After some investigation here it looks like with the 1.1.1.1 resolver from my home connection here in Hong Kong will point to up.flickr.com to 69.147.88.8 (which looks to be in the US, about 170ms and 11 hops away from a traceroute).

My previous DNS resolver points up.flickr.com to 119.161.8.12, which is much closer (apparently Korea; 9 hops, but 2.5-3ms latency only).

Besides latency, this also explains the big throughput difference I’ve been observing (5 MB/s peak with 1.1.1.1 resolver, vs. 30-40 MB/s peak with my previous DNS).

Is there something Cloudflare can do to optimize the resolution?

Connection information


#2

That is probably due to the fact that Cloudflare does not support EDNS for privacy reasons, hence Flickr cant determine your geographical location and does not return an IP closest to you but a default host.


#3

Ah I see — I thought it would also rely on anycast as I have seen otherwise little performance hits on other CDNs, so you might be right.