Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '133.173.0.0'
+557
ERRNo PTR record availible DNS server 'a13-67.akam.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.0.173.133.in-addr.arpa'.