Benchmark public DNS resolvers against your own

dnsbench.sh

#!/bin/sh

command -v bc >/dev/null || {
    echo "bc was not found. Please install bc."
    exit 1
}
{ command -v drill >/dev/null && dig=drill; } || { command -v dig >/dev/null && dig=dig; } || {
    echo "dig was not found. Please install dnsutils."
    exit 1
}

NAMESERVERS="$(grep '^nameserver' /etc/resolv.conf | cut -d " " -f 2 | sed 's/\(.*\)/&#&/')"

PROVIDERS="
$(ip route | awk '/default/ { print $3 }')#gateway
1.1.1.1#cloudflare 
4.2.2.1#level3 
8.8.8.8#google 
9.9.9.9#quad9 
80.80.80.80#freenom 
208.67.222.123#opendns 
199.85.126.20#norton 
185.228.168.168#cleanbrowsing 
77.88.8.7#yandex 
176.103.130.132#adguard 
156.154.70.3#neustar 
8.26.56.26#comodo
"

# Domains to test. Duplicated domains are ok
TESTDOMAINS="www.google.com duckduckgo.com facebook.com www.youtube.com www.reddit.com wikipedia.org github.com docs.rs git.sr.ht stackoverflow.com wiki.archlinux.org protonmail.com crates.io danielbertalan.dev freenode.net"

totaldomains=0
printf "%-18s" ""
for d in $TESTDOMAINS; do
    totaldomains=$((totaldomains + 1))
    printf "%-8s" "test$totaldomains"
done
printf "%-8s" "Average"
echo ""

for p in $NAMESERVERS $PROVIDERS; do
    pip=${p%%#*}
    pname=${p##*#}
    ftime=0

    printf "%-18s" "$pname"
    for d in $TESTDOMAINS; do
        # Sleeping to avoid possible anti-abuse
        sleep 0.1
        ttime="$($dig +tries=1 +time=2 +dnssec +stats @$pip $d | grep "Query time:" | cut -d : -f 2- | cut -d " " -f 2)"
        if [ -z "$ttime" ]; then
            # let's have timeout be 1 s = 1000 ms
            ttime=1000
        elif [ "x$ttime" = "x0" ]; then
            ttime=1
        fi

        printf "%-8s" "$ttime ms"
        ftime=$((ftime + ttime))
    done
    avg="$(echo "scale=2; $ftime/$totaldomains" | bc -lq)"

    echo "  $avg"
done

exit 0