Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '81.20.64.0'
+200
ERRNo PTR record availible DNS server 'auth21.ns.gin.ntt.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.64.20.81.in-addr.arpa'.