Check the DNS resolution time across many DNS servers.

dns_test.sh

#!/usr/bin/env bash

DEFAULT_HOSTNAME="pudim.com.br"

function help() {
    echo "DNS Test"
    echo
    echo "Check the DNS resolution time across many DNS servers."
    echo
    echo "Usage:"
    echo "   dns_test.sh [-h] [--help] [hostname]"
    echo
    echo "The default hostname ($DEFAULT_HOSTNAME) will be used if the hostname is empty"
}

while [ "$#" -gt 0 ]; do
    case "$1" in
        -h|--help)
            help

            exit 0
        ;;
    esac

    shift
done

HOSTNAME=$1

if [ -z "$HOSTNAME" ]; then
    HOSTNAME=$DEFAULT_HOSTNAME
fi

declare -A DNS_SERVERS=(
    ["Alternate DNS"]="198.101.242.72"
    ["Cloudfare"]="1.1.1.1"
    ["Comodo Secure DNS"]="8.26.56.26"
    ["DNS.WATCH"]="84.200.69.80"
    ["Dyn"]="216.146.35.35"
    ["Fourth Estate"]="45.77.165.194"
    ["FreeDNS"]="37.235.1.174"
    ["Google"]="8.8.8.8"
    ["GreenTeamDNS"]="81.218.119.11"
    ["Hurricane Electric"]="74.82.42.42"
    ["Level3"]="209.244.0.3"
    ["Neustar"]="156.154.70.1"
    ["Norton ConnectSafe"]="199.85.126.10"
    ["OpenDNS Home"]="208.67.222.222"
    ["OpenNIC"]="69.195.152.204"
    ["puntCAT"]="109.69.8.51  "
    ["Quad9"]="9.9.9.9"
    ["SafeDNS"]="195.46.39.39"
    ["SmartViper"]="208.76.50.50"
    ["UncensoredDNS"]="91.239.100.100"
    ["Verisign"]="64.6.64.6"
    ["Yandex.DNS"]="77.88.8.8"
)

echo Hostname: $HOSTNAME
echo

for DNS_SERVER in "${!DNS_SERVERS[@]}"; do
    echo "Checking $DNS_SERVER @ ${DNS_SERVERS[$DNS_SERVER]}"
    dig "$HOSTNAME" @"${DNS_SERVERS[$DNS_SERVER]}" | grep "Query time" | sed -E 's/;; //' || echo "Timed out"
    echo
done