Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '23.251.246.0'
+227
ERRNo PTR record availible DNS server 'x4.amazonaws.org' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.246.251.23.in-addr.arpa'.