68.27.217.172.in-addr.arpa name = sin10s55-in-f4.1e100.net.
68.27.217.172.in-addr.arpa name = nrt12s15-in-f68.1e100.net.
68.27.217.172.in-addr.arpa name = nrt12s15-in-f4.1e100.net.

Authoritative answers can be found from: