I did: =>dig -x 44.24.240.173 @a.ns.hamwan.net. ; <<>> DiG 9.2.4 <<>> -x 44.24.240.173 @a.ns.hamwan.net. ; (1 server found) ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55622 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;173.240.24.44.in-addr.arpa. IN PTR ;; ANSWER SECTION: *173.240.24.44.in-addr.arpa. 3600 IN PTR ae7q.hamwan.net.* ;; Query time: 147 msec ;; SERVER: 44.24.244.2#53(44.24.244.2) ;; WHEN: Thu May 15 20:44:05 2014 ;; MSG SIZE rcvd: 73 =>dig ae7q.hamwan.net. @a.ns.hamwan.net. ; <<>> DiG 9.2.4 <<>> ae7q.hamwan.net. @a.ns.hamwan.net. ; (1 server found) ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46180 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;ae7q.hamwan.net. IN A ;; AUTHORITY SECTION: *ae7q.hamwan.net. 3600 IN NS ns1.ae7q.ampr.org.* ;; Query time: 101 msec ;; SERVER: 44.24.244.2#53(44.24.244.2) ;; WHEN: Thu May 15 20:45:39 2014 ;; MSG SIZE rcvd: 64 =>dig ns1.ae7q.ampr.org. @ampr.org. ; <<>> DiG 9.2.4 <<>> ns1.ae7q.ampr.org. @ampr.org. ; (1 server found) ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27978 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 7, ADDITIONAL: 1 ;; QUESTION SECTION: ;ns1.ae7q.ampr.org. IN A ;; ANSWER SECTION: *ns1.ae7q.ampr.org. 3600 IN A 44.24.240.173* ;; AUTHORITY SECTION: ampr.org. 3600 IN NS ampr-dns.in-berlin.de. ampr.org. 3600 IN NS ampr.org. ampr.org. 3600 IN NS munnari.OZ.AU. ampr.org. 3600 IN NS ns1.defaultroute.net. ampr.org. 3600 IN NS ns2.threshinc.com. ampr.org. 3600 IN NS ns0.comgw.net. ampr.org. 3600 IN NS hamradio.ucsd.edu. ;; ADDITIONAL SECTION: ampr.org. 3600 IN A 44.0.0.1 ;; Query time: 157 msec ;; SERVER: 44.0.0.1#53(44.0.0.1) ;; WHEN: Thu May 15 20:47:46 2014 ;; MSG SIZE rcvd: 263 Now, this is not correct. While I appreciate the PTR record for 44.24.240.173, it needs to point to a *hostname* record ("A" or CNAME"), not a *domainname* record. This is not the fault of the PTR record, but the record that it points to: The NS record for ae7q.hamwan.net effectively declares ae7q.hamwan.net as a *subdomain*, with ns1.ae7q.ampr.org as its*nameserver*. Now, ns1.ae7q.ampr.org has the IP address of 44.24.240.173, but that doesn't mean that the domain ae7q.hamwan.net is anywhere near 44.24.240.x. The correct solution to this problem is to replace the NS record for ae7q.hamwan.net with a reference to a host; eg: 1. ae7q.hamwan.net. 3600 IN A 44.24.240.173 2. ae7q.hamwan.net. 3600 IN CNAME ns1.ae7q.ampr.org. The administrative advantage of the CNAME is that if my IP address changes, you don''t have to change the forward record (you'll still have to update PTR records). The administrative disadvantage is that the CNAME is dependent upon a different administrative organization. However, neither solution above allows for ae7q.hamwan.net to be a subdomain. If you want to allow ae7q.hamwan.net to be a subdomain, you need to lay the following foundation: 173.240.24.44.in-addr.arpa. 3600 IN PTR ns1.ae7q.hamwan.net. ; (or ns1.ae7q.ampr.org.) ae7q.hamwan.net. 3600 IN NS ns1.ae7q.hamwan.net. ; (or ns1.ae7q.ampr.org.) ns1.ae7q.hamwan.net. 3600 IN A 44.24.240.173 ; (if ns1.ae7q.ampr.org. is not used) That by itself will not allow *me* to add subdomain records, but it lays the foundation. I prefer creating ns1.ae7q.hamwan.net (all three records above), as it keeps the records independent of a different administrative organization. If you want to get carried away, you could also add the following record: www.ae7q.hamwan.net. 3600 IN CNAME ns1.ae7q.hamwan.net. ; (or ns1.ae7q.ampr.org.) -- Dean