![]() You'd need to include the client's subnet into the request for that. There is a EDNS Client Subnet techology that exists for a long time and allows to notify authoritative nameservers on which client's behalf you're making the request. So you will not encounter slow connection speed when visiting Google domains anymore. To avoid this in the future we configured all our DNS servers to prefer IPv4. Be careful if you're using your own recursive DNS server - with IPv6 you can't make predictions. So in the end, this turned out to be not much of a mystery. They were serving records for China instead of the records for AdGuard DNS servers location. And it seems Google failed to detect the IP address location properly when IPv6 was in use. You see, AdGuard DNS servers have several IP addresses - IPv6 as well as IPv4. AdGuard DNS has almost 50 servers over the world (and soon will have more), so why Google was returning Chinese servers' addresses to some of them? They are configured in such way so that any client gets the IP address of the closest Google server. There are four authoritative nameservers that are responsible for all of Google domains. Want to see how this whole system works for yourself? You can easily do that, for example, on this website. So we learn about two more servers and, finally, we get the answer to the initial question - what is the IP address of ? Then, one of these servers must tell us who is responsible for exactly. They are called "TLD nameservers" and they know which authoritative nameservers are responsible for each of the domains in the org zone. One of such root servers lets us know that there are 6 nameservers resonsible for the org domain zone. Their only task is to know which server is responsible for each 1st level domain zone ( com, org etc.). To do that, we address so-called root DNS servers, There are only 14 of those in the world, and you can see the entire list of them here. For the sake of example, let's imagine that you asked AdGuard DNS for an IP address of .įirst, we need to find out what server is responsiple for the org domain zone. If there's no response stored in the cache, we have to reach for the authoritative nameserver. This is true for the majority of requests, and in such case AdGuard DNS simply returns an IP address right away. It's likely that we already know what IP address corresponds to your request if that address is stored in AdGuard DNS's internal cache. Recursive DNS resolvers (like AdGuard DNS) get responses from such authoritatve nameservers.Īnd what happens when AdGuard DNS receives your DNS request? For each domain there's a DNS server that's responsible for it, a so-called authoritative nameserver. The thing is, DNS is not a centralized system. How does DNS work?įirst of all, we'll need to figure out how DNS works in general. What happened? How did it happen? We will give answers to this questions in a minute, but first we apologize for taking much more time to solve this problem than it could have taken. As expected, these addresses would work rather slowly for most users. For some domains (mainly Google-owned ones) AdGuard DNS was returning IP addresses belonging to Google China. But when it comes to IP addresses that it was returning, it's not all that good. It was doing its job just like it was designed to. Turns out, it wasn't about AdGuard DNS per se. And we couldn't have figured out the culprit - we measure speed in multiple locations all over the world, and according to our measurements it was fine in all of them.īut we finally found the root of the problem. Over the last one or two weeks we've been receiving a large amount of complaints about the AdGuard DNS's speed. Blocks trackers and dangerous sites.įree the Web from ads and protect your privacy with AdGuard Browser Extension Fights trackers and phishing.īlocks ads in browsers and supports DNS filtering. Protects your privacy.ĭoesn’t need root access to block ads in browsers and apps. Protects from phishing and malware.ĭesigned with macOS specifics in mind. Blocks ads and trackers in browsers and apps. ![]()
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