ipv4only.arpa IN A 192.0.0.170 ipv4only.arpa IN A 192.0.0.171 ipv4only.arpa IN NS a.iana-servers.net ipv4only.arpa IN NS b.iana-servers.net ipv4only.arpa IN NS c.iana-servers.net ipv4only.arpa IN NS ns.icann.org