IPv4
====

Google DNS: 8.8.8.8, 8.8.4.4
OpenDNS: 208.67.222.222, 208.67.220.220

IPv6
====

Google DNS: 2001:4860:4860::8888, 2001:4860:4860::8844d
OpenDNS: 2620:0:ccc::2, 2620:0:ccd::2