Reverse lookup ptr records not updating
A normal DNS query would be of the form 'what is the IP of host=www in domain=mydomain.com'.There are times however when we want to be able to find out the name of the host whose IP address = x.x.x.x (or x:x:x:x:x for IPv6).For example, if you have only one class C network identifier (even if you have subnetted your network), it is simplest to organize your reverse lookup zones along class C boundaries.You can add the reverse lookup zone and all the PTR resource records on an existing DNS server on your network.IPv4 reverse mapping is not mandatory though, as indicated by the mail example, it is essential for hosts that send mail, using either a Mail Transfer Agent (MTA) or a Mail User Agent (MUA).In the case of IPv6 reverse-mapping was originally mandatory but as part of the seemingly relentless move to relax the goals of the original specifications (doubtless for good operational reasons) it is no longer a mandatory requirement.
Indeed, most modern mailing systems use reverse mapping to provide simple, first-cut, authentication using a dual look-up process - IP to name and name to IP.
The reverse lookup zone exists, and I can add entries to it manually, but it doesn't automatically populate.
Dynamic updates are enabled for both the forward and reverse zones. This could be due to a couple of different things: 1) Are your clients obtaining IPs via a Windows DHCP Server?
The following sections explain where to put reverse lookup zones and how to create, configure, and delegate them.
For information about any of the IP addressing concepts discussed in the following sections, see "Introduction to TCP/IP" in this book.
It seems to have fallen into the Jolly Useful ™ category. IP Addresses are allocated in blocks from IANA (currently managed by ICAAN) through the Regional Internet Registries (RIRs), which it turn may allocate them to National Internet Registries (NIRs - though this national level is not always present) and so down to what are called Local Internet Registries (LIRs) which are typically ISPs/SPs.