/etc/named.conf :

key DHCP_UPDATER {
  algorithm HMAC-MD5.SIG-ALG.REG.INT;
  #secret RdmrPr8EtJ9KCYOzrdMyBg==;
  secret PJG5+iDkLgLFsbXhY0Zz0g==;
};

  zone "linuxhotel.de" {
        type master;
        file "dyn/linuxhotel.de";
        allow-update { key DHCP_UPDATER; };
         notify yes;
  };

  zone "1.168.192.in-addr.arpa" {
        type master;
        file "dyn/1.168.192.in-addr.arpa";
        allow-update { key DHCP_UPDATER; };
        notify yes;
  };

/etc/dhcpd.conf : openSuSE 12.1

authoritative;
ddns-update-style interim;
ignore  client-updates;
use-host-decl-names on;
subnet 192.168.1.0 netmask 255.255.255.0 {
  range 192.168.1.50 192.168.1.99;
  option domain-name-servers 192.168.1.6;
  option domain-name "linuxhotel.de";
  option routers 192.168.1.1;
  option broadcast-address 192.168.1.255;
  default-lease-time 3600;
  max-lease-time 7200;
}

key DHCP_UPDATER {
  algorithm HMAC-MD5.SIG-ALG.REG.INT;
  secret PJG5+iDkLgLFsbXhY0Zz0g==;
};

zone linuxhotel.de. {
  primary 127.0.0.1;
  key DHCP_UPDATER;
}

zone 1.168.192.in-addr.arpa. {
  primary 127.0.0.1;
  key DHCP_UPDATER;
}

host vm43 {
  hardware ethernet 52:54:00:00:01:42;
  ddns-hostname vm43;
}

# Statische Einträge im DNS einzutragen wird vom ISC nicht empfohlen. 
# Wenn man das macht, werden bei 
# Änderung der IP-Adresse die alten PTR-Records nicht entfernt. 
update-static-leases on;
host testzy {
  hardware ethernet 52:54:00:00:01:23;
  fixed-address 192.168.1.111;
  ddns-hostname testzy;
}