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A comment on the article makes a good point that this seems to break resolution of IPs based on geography. Perhaps CloudFlare takes this into account with their
by michaelmior 13y ago
A comment on the article makes a good point that this seems to break resolution of IPs based on geography. Perhaps CloudFlare takes this into account with their caching mechanism, but this is unclear.
- samcrawford 13y agoIt's hard to see how they could account for it perfectly. I suppose they could inject an EDNS client subnet option into the request they make upstream (with the original client's IP here), but that assumes that the target supports this option.
- justincormack 13y agoResolution of IPs based on geography is already fairly broken in many cases. But it should resolve based on where the cloudflare server is, which should be ok.
- michaelmior 13y agoThat's the point. This is arguably worse than resolving based on the location of the client. Although if the server doing the caching is an edge server already located close to the client, this is less of an issue.
- jgrahamc 13y agoCloudFlare does Anycast for both DNS and HTTP so the DNS resolver will be 'close' to the client and the HTTP connection will be made automatically to the 'closest' CloudFlare PoP.
- dfc 13y agoGoogle DNS and OpenDNS also cause some serious problems with geographic results. My go to example is www.netflix.com. I live in NY and Google DNS always points me to us-west instead of us-east. dfc@fob-xray:~$ host www.netflix.com # local unbound dns www.netflix.com is an alias for www.us-east-1.netflix.com. www.us-east-1.netflix.com is an alias for www.us-east-1.prodaa.netflix.com. www.us-east-1.prodaa.netflix.com has address 50.16.245.238 www.us-east-1.prodaa.netflix.com has IPv6 address 2406:da00:ff00::6b14:f251 dfc@fob-xray:~$ host www.netflix.com 8.8.8.8 # 8.8.4.4 Gives same response Using domain server: Name: 8.8.8.8 Address: 8.8.8.8#53 Aliases: www.netflix.com is an alias for www.us-west-2.netflix.com. www.us-west-2.netflix.com is an alias for www.us-west-2.prodaa.netflix.com. www.us-west-2.prodaa.netflix.com has address 54.245.96.95 www.us-west-2.prodaa.netflix.com has IPv6 address 2620:108:700f::3270:5f36
- eli 13y agoStrange, 8.8.8.8 appears to be anycast and resolves to a east coast server for me, so I correctly get us-east-1 for netflix when I query it FWIW, Google has proposed a solution to this problem: http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-01 http://tools.ietf.org/html/draft-vandergaast-edns-client-sub...
- jlgaddis 13y agoAssuming the user is hitting their nearest CloudFlare location, this should be less of an issue.