Two subnets, one with PXE clients

[osmany at oc.quimefa.cu]

Greetings,

I would like some help in configuring my DHCP. Currently I am running
ubuntu server 9.04 with dhcp3. I have successfully configured it with
dynamic dns updates. Recently I had to install and configure an LTSP server
but I would like to use the same DHCP to assign IP addresses to he PXE
Clients but here is the thing; I would like to work with the PXE Clients on
the same physical network but on a separate subnet. For example I would
like the windows XP clients to work on the 10.25.4.0/24 subnet and the PXE
Clients to work on the 192.168.0.0/24 subnet, of course I have a second NIC
installed and configured. In other words it should a setup so that the PXE
Clients would never get an IP from the normal XP clients and vice versa.
How can I do this?

I was thinking about it and I came up with some thing like this:

authoritative;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
ddns-updates on;
ddns-update-style interim;
ignore client-updates;


include "/etc/bind/rndc.key";

zone domain.{
        primary 127.0.0.1;
        key rndc-key;
}

zone 4.25.10.in-addr.arpa.{
        primary 127.0.0.1;
        key rndc-key;
}

include "/etc/bind/rndc.key";

zone domain.{
	primary 127.0.0.1;
	key rndc-key;
}

zone 4.25.10.in-addr.arpa.{
	primary 127.0.0.1;
	key rndc-key;
}

subnet 10.25.4.0 netmask 255.255.255.0 {
	option ntp-servers 10.25.4.6;
	option ip-forwarding off;
	option domain-name "oc.quimefa.cu";
	option domain-name-servers 10.25.4.8;
	ddns-domainname "domain.";
	ddns-rev-domainname "4.25.10.in-addr.arpa.";
	range 10.25.4.20 10.25.4.46;
	range 10.25.4.48 10.25.4.51;
	range 10.25.4.53 10.25.4.78;
	range 10.25.4.80 10.25.4.94;
	range 10.25.4.172 10.25.4.210;
	range 10.25.4.212 10.25.4.229;
	option routers 10.25.4.1;
	option broadcast-address 10.25.4.255;
	deny members of "PXEClients";
}

class "PXEClients" {
	match if substring (option vendor-class-identifier, 0, 3)="PXE";
	one-lease-per-client on;
	next-server 192.168.0.2;
	filename "/ltsp/pxelinux.0";
	option root-path "/opt/ltsp/i386";
	allow booting;
	allow bootp;
}

subnet 192.168.0.0 netmask 255.255.255.0 {
	option subnet-mask 255.255.255.0;
	option broadcast-address 192.168.0.255;
	range 192.168.0.4 192.168.0.50;
	allow members of "PXEClients";
}


I really would appreciate any help on this. thank you.