Unable to find any PTR-records for the specified domain/ip :(
Log
+001
Resolving PTR record of '2600:1fa0:4100::'
+139
ERRNo PTR record availible DNS server 'pdns1.ultradns.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.4.0.a.f.1.0.0.6.2.ip6.arpa'.