Description Dirk Ahrnke 2023-04-11 12:23:45 CEST

A "DHCP Dynamic DNS" policy can contain a "DDNS domain name" and a "DDNS reverse domain name". 
There is no further documentation about the syntax and the hover-text simply says "domain name that will be appended..."
When simply adding a domain name one will (hopefully) notice that the DHCP server refuses to start because the syntax of "ddns-domainname" and "ddns-rev-domainname" needs a quoted string which has to be defined in the policy.

valid:
root@dn-hb01:/etc/dhcp# udm policies/dhcp_dnsupdate list

DN: cn=DDNS-Bremen,cn=policies,dc=training,dc=ucs
  clientUpdates: allow
  ddnsDoForwardUpdate: true
  ddnsDomainname: "bremen.training.ucs"
  ddnsHostname: None
  ddnsRevDomainname: "bremen.training.ucs"
  ddnsUpdateStyle: ad-hoc
  ddnsUpdates: on
  ldapFilter: None
  name: DDNS-Bremen
  updateStaticLeases: None

invalid:

root@dn-hb01:/etc/dhcp# udm policies/dhcp_dnsupdate list

DN: cn=DDNS-Bremen,cn=policies,dc=training,dc=ucs
  clientUpdates: allow
  ddnsDoForwardUpdate: true
  ddnsDomainname: bremen.training.ucs
  ddnsHostname: None
  ddnsRevDomainname: bremen.training.ucs
  ddnsUpdateStyle: ad-hoc
  ddnsUpdates: on
  ldapFilter: None
  name: DDNS-Bremen
  updateStaticLeases: None

root@dn-hb01:/etc/dhcp# grep ddns /var/log/dhcp-ldap-startup.log 
ddns-domainname bremen.training.ucs;
ddns-rev-domainname bremen.training.ucs;
ddns-update-style ad-hoc;
ddns-updates on;

Apr 11 12:22:21 dn-hb01 systemd[1]: Starting ISC DHCP Server for IPv4...
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: LDAP line 12: semicolon expected.
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: ddns-domainname bremen.
Apr 11 12:22:21 dn-hb01 dhcpd[7854]:                        ^
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: LDAP line 12: expecting a parameter or declaration
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: ddns-domainname bremen.training.ucs;
Apr 11 12:22:21 dn-hb01 dhcpd[7854]:                                     ^
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: LDAP: cannot parse dhcpService entry 'cn=training.ucs,cn=dhcp,dc=training,dc=ucs'
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: Configuration file errors encountered -- exiting
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: 
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: If you think you have received this message due to a bug rather
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: than a configuration issue please read the section on submitting
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: bugs on either our web page at www.isc.org or in the README file
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: before submitting a bug.  These pages explain the proper
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: process and the information we find helpful for debugging.
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: 
Apr 11 12:22:21 dn-hb01 dhcpd[7854]: exiting.
Apr 11 12:22:21 dn-hb01 systemd[1]: isc-dhcp-server.service: Control process exited, code=exited, status=1/FAILURE
Apr 11 12:22:21 dn-hb01 systemd[1]: isc-dhcp-server.service: Failed with result 'exit-code'.
Apr 11 12:22:21 dn-hb01 systemd[1]: Failed to start ISC DHCP Server for IPv4.
^C