Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '2600:9000:25b3::'
+347
ERRNo PTR record availible DNS server 'x4.amazonaws.org' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.b.5.2.0.0.0.9.0.0.6.2.ip6.arpa'.