This user account only needs limited privileges, it must be a member of DNSAdmins, DNSUpdate Proxy, DHCP Users and DHCP Administrators.
Error 31, DNS Update Failed – Seen this one before? The place to look for logs is: C:\Windows\System32\dhcp, check yours out and see if you have any error 31’s.
Once you have these credentials set, restart your DHCP server service.
Before we delve any further, its time to check your DNS setup, ensure that DNSAdmin’s have full control over the entire DNS infrastructure, by going to properties and security tab on each DNS server.
Besides from running my own separate DNS server, what's a Linux Sys Admin to do?
The I'm willing to bet that the System Administrator running your Windows DHCP server is requiring secure Dynamic DNS updates.