I have an odd DNS issue that only sometimes presents itself.
I have several Linux machines, running Ubuntu (10.10, 11.10, 12.04). Sometimes, however, the system gets an IP address from DHCP, but fails to update the DNS server with it's hostname and IP.
Here is how you can enable the DNS integration with the Windows Server 2012 DHCP server: Once done, click OK to save the changes that you have made.You can approach this by manually forcing the clients to check in.You might be able to do this by tweaking some group policy settings, or by running a script to bulk "ipconfig /registerdns" on a bunch of clients.I'm afraid that you're going to have to approach this from the client end.Changing the timeouts is only going to help clients the next time they check in, which is usually after half the existing lease time, or sometimes during boot.
The I'm willing to bet that the System Administrator running your Windows DHCP server is requiring secure Dynamic DNS updates.