Re:A cartoon intro to DNS over HTTPS (2018)
by throw0101a on Sunday October 20, 2019 @09:44AM
(#21304084)
> Aside: I've never understood how DNS is decentralized.
I use my ISP's recursive DNS resolvers (or not); you use your ISP's recursive DNS resolvers (or not). Anyone that wants to track "everyone's" browsing has to track a whole bunch of ISPs (and 3rd party DNS operators) if they want to keep a database of activity. There is no central facility that has everyone's DNS requests, unlike (e.g.) MSN Messenger back in the day where all traffic was transferred through the central system.
Further, because of caching, it is impossible to get exact numbers on people querying DNS. So while the records for www.youtube.com are in a central place, the exact number of people sitting on their couches at home asking for the A record is masked by people's home routers doing caching and also their ISP DNS servers (which the home routers talk to) doing caching.
So there is no "central DNS" server that does hostname-to-IP mapping: there are (tens of) thousands--millions if you count people's home Linksys/Dlink/Asus routers running dnsmasq (or whatever).
I use my ISP's recursive DNS resolvers (or not); you use your ISP's recursive DNS resolvers (or not). Anyone that wants to track "everyone's" browsing has to track a whole bunch of ISPs (and 3rd party DNS operators) if they want to keep a database of activity. There is no central facility that has everyone's DNS requests, unlike (e.g.) MSN Messenger back in the day where all traffic was transferred through the central system.
Further, because of caching, it is impossible to get exact numbers on people querying DNS. So while the records for www.youtube.com are in a central place, the exact number of people sitting on their couches at home asking for the A record is masked by people's home routers doing caching and also their ISP DNS servers (which the home routers talk to) doing caching.
So there is no "central DNS" server that does hostname-to-IP mapping: there are (tens of) thousands--millions if you count people's home Linksys/Dlink/Asus routers running dnsmasq (or whatever).