Measure DNS speed by query Alexa top 50 sites NS and A record

alexa-top-50-sites-dns-bench.sh

#!/bin/bash
TEMP=/tmp/alexa.html

if [ -z $1 ] ; then
    echo "`basename $0` {dns}"
else
    DNS=$1
    [ -f $TEMP ] || curl -s https://www.alexa.com/topsites > $TEMP
    T1=`date +%s.%N`
    for HOST in `awk -F[\"\/] '/href=..siteinfo\// {print $4}' $TEMP`
    do
        echo $HOST
        dig NS $HOST @$DNS
        dig A $HOST @$DNS
    done
    T2=`date +%s.%N`
    echo -n "Total time "`echo $T2-$T1 | bc -l`    
fi