Unable to find any PTR-records for the specified domain/ip :(
Log
+000
Resolving PTR record of '129.134.172.0'
+116
ERRNo PTR record availible DNS server 'a.ns.facebook.com' raised an NotExistentDomain error, while beeing queried for PTR-records on domain '0.172.134.129.in-addr.arpa'.