Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '148.163.131.0'
+251
ERRNo PTR record availible DNS server 'ns3.proofpoint.com' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.131.163.148.in-addr.arpa'.