We have two 2008 R2 DHCP servers (which also run AD/DNS). I've noticed that any new device I put on the network has a tendency to lose it's DNS registration in the forward look-up zone (or possibly they never had one). I can successfully register it with 'ipconfig /registerdns', after which time it will "stick" and never have a problem again. However, I'm staring at several machines, some of which are newly provisioned servers, which have a DHCP lease and no record in DNS (they aren't the kind of servers that need a static address). We also have hundreds of workstations I know are missing from DNS (though this is less of an issue). They DO have a PTR record, which is always updated properly - it's just the A record that doesn't get updated unless you manually register. I understand that in Windows 2000+, the client should update the A record and the DHCP server updates the PTR in the default configuration, so only the latter appears to be working.
The DNS zone is set to "secure only" updates. Scavenging period 9 hours with 12hour no-refresh+12hour refresh. We have DHCP set to "dynamically update A and PTR records only if requested by the DHCP clients" and discard when lease is deleted. Name protection is not enabled. We use a shared service account for DNS Dynamic updates.
I've checked the workstation in question to make sure they aren't getting any weird GPO that would influence this behavior (they aren't, from what I can tell). The only DNS/DHCP-related policy they receive is a 60-minute refresh interval for DHCP. The option to "register this connection's address in DNS" is checked - everything is pretty vanilla on the workstations, nothing odd there that I can see (and we have this issue for all flavors of Windows as well as non-Windows devices like iDrac cards).
Paul Hite - MCSE, MCITP