ddns update for machines that changed subnet

[amoroder]

Hello,

we have dhcp that updates the DNS. This worked fine for many years.
Now we have to migrate many PCs to another network. When dhcp tries
to
update the entries in bind then we get the following errors

Oct 13 10:00:01 voyager2 named[11709]: error processing update packet
(YXRRSET) id 30767 from [127.0.0.1].45121
Oct 13 10:00:01 voyager2 dhcpd: if IN A LATD620-AM.sb-brixen.it rrset
doesn't exist add 1750 IN A LATD620-AM.sb-brixen.it 10.53.1.144:
RRset
already exists.

dhcpd and named are on the same server.

in my named.conf I have


zone "sb-brixen.it" in {
        type master;
        file "sb-brixen.zone";
        allow-update { key DHCP_UPDATER; };
};


zone "53.10.in-addr.arpa" in {
        type master;
        file "10.53.zone";
        allow-update { key DHCP_UPDATER; };
};


In my dhcpd.conf

ddns-domainname "sb-brixen.it";
ddns-update-style ad-hoc;


Is there a way to tell dns to delete the old record and add the new
when
the IP address changes ?

Thanks
Andreas