Implement of checking existing higher class ip reverse zones
Implement of checking existing higher class ip reverse zones

iteratively checking of existing domains with higher IP
classes. When this function find an existing higher class
domain return with that reverse address. eg. 192.in-addr.arpa

If it is not find  any existing higher class domain it returns with the lowest class domain reverse domain name. eg, 39.168.192.in-addr.arpa
ngoduykhanh/PowerDNS-Admin,ngoduykhanh/PowerDNS-Admin,ngoduykhanh/PowerDNS-Admin,ngoduykhanh/PowerDNS-Admin