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Ask HN: Why DNS resolvers don't use HTTP?
Can they simply use REST JSON API? Do you think it will slow down normal browsing?
- db48x 9y agoDNS predates REST, JSON, and HTTP. DNS gets great utility out of the UDP protocol, which would be lost by using TCP. Parsing the JSON would ruin DNS server performance (a DNS server can answer hundreds of queries in the time it takes to parse one JSON message).
- ggm 9y agoTruncate forces TCP. DOH or DNS over https is in standards process as is DNS over TLS and DNS over quic
- schoen 9y agoThere is a new protocol from Google to do this: https://developers.google.com/speed/public-dns/docs/dns-over-https https://developers.google.com/speed/public-dns/docs/dns-over... The traditional reason that DNS doesn't use HTTP is (1) published DNS standards predate published HTTP standards by 9 years, and predate the mainstream popularity of the web by even more than that (so HTTP didn't even exist when DNS was created, nor was there any such thing as a firewall that only permitted HTTP traffic); (2) HTTP requires more roundtrips, which add more latency, while a UDP-based DNS connection can usually be answered in a single roundtrip. However, Google has pointed out that their DNS-over-HTTPS approach can improve security and privacy. Presumably it will inherently be slightly higher latency because you need a couple of roundtrips for the TCP and TLS setup even before you can send a query.