“fastest” / “best” Upstream DNS server(s) for adguard, why choose or benchmark? just parallel requests it all
Whilst tools like DNS benchmark exist, I overlooked a very simple option available in adguard named “parallel requests”, this will query all the upstream DNS servers you define, and whatever server replies the fastest will grant you a reply.
Meaning you no longer have to look for the best performing one, let them race each other 😃 so it’s possible google replies the fastest the one time, or quad9 the other time, or maybe your private Unbound is faster?


You can even put multiple technologies like QUIC, DoT (DNS over TLS) and DoH (DNS over HTTPS), in case one would fail, or a provider would have a small hiccup for whatever reason
From time to time I would benchmark what DNS server would reply the fastest since I always overlooked the parallel requests option, with this, it really doesn’t matter anymore, if your list contains some generally “fast” DNS upstream servers.
My list (sourced from list of known DNS providers )
https://security.cloudflare-dns.com/dns-query tls://security.cloudflare-dns.com https://dns.quad9.net/dns-query tls://dns.quad9.net https://dns.adguard.com/dns-query tls://dns.adguard.com

All the servers!
If you just care about speed, I have compiled a list(s) of DNS-over-HTTPS / DNS-over-TLS / DNS-over-QUIC / fuck-it-give-me-all-the-servers-list
DNSSEC
small remark: do enable DNSSEC even when you are using DoT / DoH check out why here

