/etc/dhcp/dhcp-subnet.include

# Dynamic Hosts
# (10.0.1.16->128)
subnet 10.0.1.0 netmask 255.255.255.0 {
       pool {
            range 10.0.1.16 10.0.1.128;
            deny dynamic bootp clients;
            use-host-decl-names true;
       }
}       
# Fixed address for known host
# (10.0.1.129->)
pool {
    host myserver1
        hardware ethernet AA:BB:CC:DD:EE:FF;
        fixed-address 10.0.1.129;
    }
    host myserver2
        hardware ethernet 00:11:22:33:44:55;
        fixed-address 10.0.1.130;
    }
}

generic dynamic IP Range

we know these computers

In general, for the Fixed addresses, we change the lease time to maximum, especially if this is not laptops, like server or desktop computers.