block / exclude or deny single IP addresses from being handed out

[Chris Henderson]

My DHCP server (v 3.0.6) has an include file which is dynamically
generated by a script. However, I would like to exclude some single
IPs from the /etc/dhcpd.conf file so that they are never being handed
out to the clients. These IPs are: 192.168.1.25, 192.168.2.25,
192.168.3.25, 192.168.4.25.

Does anyone know how to do that?

Thanks.