Dear Hostmaster, There are empty reverse zone files for RFC1918 private IP addresses (10/8, 172.16/12, 192.168/16). E.g. 16.172.in-addr.arpa. 86400 SOA zed.isi.edu. bmanning.zed.isi.edu. ( 1928512 ; serial 10800 ; refresh (3 hours) 900 ; retry (15 mins) 3600000 ; expire (41 days 16 hours) 86400 ) ; minimum (1 day) 16.172.in-addr.arpa. 86400 NS NS.isi.edu. 16.172.in-addr.arpa. 86400 NS RS0.INTERNIC.NET. (However ns.isi.edu contains no data about these zones.) Is this intentional? Maybe it would be useful to revoke this fake delegations, and leave peoples to put arbitrary entries into initial cache file of their DNS. I mean that if a smaller community want to use some private IP addresses, they could set up local reverse DNS-s for them. If all DNS of the community contains an entry in cache file like this 168.192.in-addr.arpa. NS local-reverse-ns.some.organization. subdomains could be delegated in the usual way, and local peoples could see "nice" traceroutes across local point-to-point links with RFC1918 addresses. Any comments? Regards Gabor Kiss