Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '163.123.173.0'
+182
ERRNo PTR record availible DNS server 'apnic.authdns.ripe.net' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.173.123.163.in-addr.arpa'.