DHCP and TAP devices

I have clients with TAP network interfaces, I can get the dhcp information
from the server. the problem is I need one scope for actual network
interfaces, and one scope for TAP network interfaces. the only way to
indentify the TAP devices is that there MAC address starts with 00:FF

here is an example of what I need in a BIND configuration file.


class "test" {
match if substring (hardware, 1, 2) = 00:FF;
}
authoritative;
subnet 172.16.0.0 netmask 255.255.255.0 {
always-broadcast on;
max-lease-time 3600;
default-lease-time 1800;
option domain-name "ezone.net";
option subnet-mask 255.255.255.0;
pool {
deny members of "test";
range 172.16.0.150 172.16.0.254;
option routers 172.16.0.1;
option domain-name-servers 172.16.0.1;
}
pool {
allow members of "test";
range 172.16.0.100 172.16.0.125;
option domain-name-servers 172.16.0.1;
}
}