146 read and no answers...
That topic is not solved and is a real pain.
This is a very basic feature of a system like Zentyal, to register DHCP leases into the DNS. If it's broken, you can't claim to have DNS and DHCP sync'ed.
I could setup a DNS with DHCP and get every new leases register to DNS without a problem on Ubuntu 18.04, but Zentyal is using scripts and templates so I could not patch my system. Look like a Kerberos key problem or at least some bad permissions somewhere.
I'm not sure that product is still under developpement, this is a real bug preventing Zentyal to do his work, leaving it totally useless.
Tested with 6.0 (not modded):
Apr 13 17:31:03 tech01 dhcpd[9630]: DHCPREQUEST for 192.168.0.50 from 3e:d9:4b:7a:08:3b (centreon) via eth0
Apr 13 17:31:03 tech01 dhcpd[9630]: DHCPACK on 192.168.0.50 to 3e:d9:4b:7a:08:3b (centreon) via eth0
Apr 13 17:31:03 tech01 named[9312]: samba_dlz: starting transaction on zone domain.lan
Apr 13 17:31:03 tech01 named[9312]: samba_dlz: spnego update failed
Apr 13 17:31:03 tech01 named[9312]: client @0x7f05e86caa20 127.0.0.1#49095/key domain.lan: updating zone 'domain.lan/NONE': update failed: rejected by secure update (REFUSED)
Apr 13 17:31:03 tech01 named[9312]: samba_dlz: cancelling transaction on zone domain.lan
Apr 13 17:31:03 tech01 dhcpd[9630]: Unable to add forward map from centreon.domain.lan. to 192.168.0.50: REFUSED
Apr 13 17:32:20 tech01 named[9312]: resolver priming query complete