A quick dns propagation checker in BASH.

dnsPropagationCheck.sh

#!/usr/bin/env bash
# --------------------------------------------------------------------------------------------------
# dnsPropagationCheck.sh
#
# NOTE: Requires dnsServers.txt. Example:
#
#8.8.8.8           Google_1
#8.8.4.4           Google_2
#9.9.9.9           Quad9_1
#149.112.112.112   Quad9_2
#77.88.8.1         Yandex_1
#77.88.8.8         Yandex_2
#208.67.222.222    OpenDNS_1
#208.67.220.220    OpenDNS_2
#209.244.0.3       Level3_1
#209.244.0.4       Level3_2
#216.146.35.35     DYN_1
#216.146.36.36     DYN_2
#8.26.56.26        Comodo_1
#8.20.247.20       Comodo_2
#64.6.64.6         UltraDNS_1
#64.6.65.6         UltraDNS_2
#1.1.1.1           Cloudflare_1
#1.0.0.1           Cloudflare_2
#185.228.168.9     CleanBrowsing_1
#185.228.169.9     CleanBrowsing_2
#64.6.64.6         Verisign_1
#64.6.65.6         Verisign_2
#176.103.130.130   AdGuard_1
#176.103.130.131   AdGuard_2
#
# --------------------------------------------------------------------------------------------------
# Help
# --------------------------------------------------------------------------------------------------

help="\

NAME
      dnsPropagationCheck.sh

SYNOPSIS
      ${0##*/} [-h] [-t \e[04mtype\e[0m] [-d \e[04mdomain\e[0m]

DESCRIPTION
      Retrieves the TTL of a DNS record from across many DNS servers.

      The following options are available:

      -h    Print this menu.

      -t \e[04mtype\e[0m
            Specify the record type to check.

      -d \e[04mdomain\e[0m
            Specify the domain name to check.


EXAMPLES
      The following retrieves the TTL of www.nike.com from accross man DNS servers.

          ./dnsPropagationCheck.sh -t cname -d www.nike.com

"

printHelp() {
  echo -e "$help" >&2
}

# --------------------------------------------------------------------------------------------------
# Sanity (1/2)
# --------------------------------------------------------------------------------------------------

if [[ "$1" != '-h' && $# -lt 4 ]]; then
  printHelp
  exit 1
fi

if [[ ! -f dnsServers.txt ]]; then
  echo -e "\e[01;31mERROR\e[0m: The file 'dnsServers.txt' is required."
  exit 1
fi

# --------------------------------------------------------------------------------------------------
# Arguments
# --------------------------------------------------------------------------------------------------

OPTIND=1
while getopts "ht:d:" opt; do
  case $opt in
    h)
      printHelp
      exit 0
      ;;
    t)
      arg_t='set'
      arg_t_val=("$OPTARG")
      ;;
    d)
      arg_d='set'
      arg_d_val=("$OPTARG")
      ;;
    *)
      echo -e "\e[01;31mERROR\e[00m: Invalid argument!"
      printHelp
      exit 1
      ;;
  esac
done
shift $((OPTIND-1))

# --------------------------------------------------------------------------------------------------
# Sanity (2/2)
# --------------------------------------------------------------------------------------------------

if [[ "$arg_t" == 'set' && "$arg_d" != 'set' ]]; then
  echo -e "\e[01;31mERROR\e[0m: Both the DNS record type and domain name must be specified."
  printHelp
  exit 1
fi

if [[ "$arg_t" != 'set' && "$arg_d" == 'set' ]]; then
  echo -e "\e[01;31mERROR\e[0m: Both the DNS record type and domain name must be specified."
  printHelp
  exit 1
fi

# --------------------------------------------------------------------------------------------------
# Variables
# --------------------------------------------------------------------------------------------------

recordType="$arg_t_val"
domain="$arg_d_val"

printf "\e[04mQuery Summary:\e[0m\n"
printf "  Record Type: $recordType\n"
printf "  Record Name: $domain\n\n"
col1="\e[04mServer\e[0m"
col2="\e[04mTTL\e[0m"
col3="\e[04mValue\e[0m"
printf "$col1"
printf '%*s' "$((${COLUMNS}-$((${COLUMNS}-$(wc -c<<<$col1)+60))))"
printf "$col2"
printf '%*s' "$((${COLUMNS}-$((${COLUMNS}-$(wc -c<<<$col2)+6))))"
printf "$col3\n"
while read -r line; do
  server=$(awk '{print $1}' <<< $line)
  name=$(echo $line | cut -d' ' -f2- | awk '{$1=$1;print}')
  unset ttl
  if nc -zv -w 1 $server 53 2>/dev/null; then
    response=$(dig ${recordType} @${server} +tcp +noall +answer ${domain} | head -n1)
    ttl=$(echo "$response" | awk '{print $2}')
    [[ -z $ttl ]] && ttl='na'
    val=$(echo "$response" | awk '{print $5}')
    [[ -z $val ]] && val='na'
    printf "$server"
    printf '%*s' "$((${COLUMNS}-$((${COLUMNS}-$(wc -c<<<$server)+19))))"
    printf "$name"
    printf '%*s' "$((${COLUMNS}-$((${COLUMNS}-$(wc -c<<<$name)+31))))"
    printf "$ttl"
    printf '%*s' "$((${COLUMNS}-$((${COLUMNS}-$(wc -c<<<$ttl)+13))))"
    printf "$val\n"
  else
    printf "ERROR: DNS server ${server} (${name}) could not be reached.\n"
  fi
done <<< $(cat dnsServers.txt)

Outputs like:

$ ./dnsPropagationCheck.sh -t a -d  nike.com
Query Summary:
  Record Type: a
  Record Name: nike.com

Server                                          TTL         Value
8.8.8.8           Google_1                      60          13.33.165.56
8.8.4.4           Google_2                      60          13.33.165.56
9.9.9.9           Quad9_1                       60          108.156.120.116
149.112.112.112   Quad9_2                       60          108.156.120.116