Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '192.50.252.0'
+786
ERRNo PTR record availible DNS server 'dns-b.iij.ad.jp' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.252.50.192.in-addr.arpa'.