Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '133.238.8.0'
+508
ERRNo PTR record availible DNS server 'dns1.iij.ad.jp' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.8.238.133.in-addr.arpa'.