We'll see here the Reverse DNS delegation mechanism in full details, the practical Reverse DNS implementation, as well as the debugging techniques. Please be sure to have read the first two parts, as they lay som basic principles : part1 part2 .We'll only see some Reverse DNS Specifics here.
The Reverse DNS authority delegation
The Reverse DNS authority delegation follows the IP scopes address delegation. The IANA gives a scope of addresses to a RIR. This RIR handles a subset of this scope to an ISP or Tunnel Broker. Finally, the ISP / Tunnel Broker handles a sub-subset of that scope the custommer. [ The scope portions depicted here are fictionnary and illustrative only ) :
Reverse DNS Practical Delegation
In a case of a single public IP, either IPv4 or ' IPv6 WAN ' ( CPE WAN or IPv6 Tunnel Endpoint ), the ISP/Tunnel Broker usually only allows settings through its management interface ( webpage ).
In case of a full scope ( which is quite common with IPv6 ), the ISP/Tunnel Broker may allow external control of the Reverse DNS through a DNS Servers duo. The requierments are the same as with domain zone delegation ( link ) :
. 2 NS Records in the ISP DNS Servers
. at least 1 Glue record related to these 2 NS Records at the ISP DNS Servers
. 2 Network-topologically distinct DNS Servers with the same zone record :
. 1 SOA Record
. 2 NS records
. A or AAAA records for the Name Servers :
Reverse DNS NSLOOKUP verifications
( to be completed )