Effects of secured DNS transport on resolver performance

Etienne Le Louet (1, 2) , Antoine Blin (2) , Julien Sopena (1) , Ahmed Amamou (2) , Kamel Haddadou (2)

1 DELYS - DistributEd aLgorithms and sYStems
2 Gandi SAS

Designed 40 years ago, DNS is still a core component of internet: billions of DNS queries are processed each day to resolve domain names to IP addresses. Originally designed for performances and scalability, its transport protocol is unencrypted, leading to security flaws. Recently, secure protocols have emerged, but the question of their scalability and sustainability remains open. In this paper we study the cost of switching from the legacy DNS transport to the newer ones, by first characterising the shape of the traffic between clients and secured public resolvers. Then, we replicate said traffic, to measure the added cost of each protocol. We found that, while connections usually stayed open, many closures and openings were made in some cases. Comparing these profiles over different DNS transports, we observe that switching from the legacy protocol to a more secure one can lead to an important performance penalty.

Mots clés: Benchmark; DNS; DNS security; DNS over HTTPS; TLS; DNS resolvers; HTTPS

Domaines: Informatique [cs]; Réseaux et télécommunications [cs.NI]

Etienne Le Louet, Antoine Blin, Julien Sopena, Ahmed Amamou, Kamel Haddadou. Effects of secured DNS transport on resolver performance. 2023 IEEE Symposium on Computers and Communications (ISCC), Jul 2023, Gammarth, Tunisia. pp.238-244, ⟨10.1109/ISCC58397.2023.10217887⟩. ⟨hal-04220131⟩