DNS/free-and-publicについて、ここに記述してください。
https://www.lifewire.com/free-and-public-dns-servers-2626062
Free & Public DNS Servers (Valid April 2017)
Provider Primary DNS Server Secondary DNS Server Level3 209.244.0.3 209.244.0.4 Verisign 64.6.64.6 64.6.65.6 Google 8.8.8.8 8.8.4.4 DNS.WATCH 84.200.69.80 84.200.70.40 Comodo Secure DNS 8.26.56.26 8.20.247.20 OpenDNS Home 208.67.222.222 208.67.220.220 Norton ConnectSafe 199.85.126.10 199.85.127.10 GreenTeamDNS 81.218.119.11 209.88.198.133 SafeDNS 195.46.39.39 195.46.39.40 OpenNIC 96.90.175.167 193.183.98.154 SmartViper 208.76.50.50 208.76.51.51 Dyn 216.146.35.35 216.146.36.36 FreeDNS 37.235.1.174 37.235.1.177 Alternate DNS 198.101.242.72 23.253.163.53 Yandex.DNS 77.88.8.8 77.88.8.1 UncensoredDNS 91.239.100.100 89.233.43.71 Hurricane Electric 74.82.42.42 puntCAT 109.69.8.51