Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '216.9.237.0'
+234
ERRNo PTR record availible DNS server 'x.arin.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.237.9.216.in-addr.arpa'.