Comment by StreamBright
7 years ago
>> The urban legend that DNS-based load balancing depends on TTLs (it doesn’t - since Netscape Navigator, clients pick a random IP from a RR set, and transparently try another one if they can’t connect)
Unless you do not return an RR set and what you return is based on geolocation and data center health.
Uhm, how does this work with "global" DNS services which people tend to use more and more? (Eg. Cloudflare's 1.1.1.1 or Google's 8.8.8.8/8.8.4.4)
Basically, your request is coming from them and wherever their servers are (US, I guess, though they probably have several data centers) and they route it to the final user.
I think using DNS-based geolocation sounds like a really bad idea: what am I missing?
The EDNS0 client-subnet extension exists for this exact reason.
Thanks. It seems, unfortunately, that only Google DNS and OpenDNS (Cisco iirc) include the data as of now. Older articles even mention how you have to have your website (well, nameservers) whitelisted for them to forward client subnet as part of DNS queries, not sure if that is still the case.
Of course, caching gets more complicated and less useful with this.