You do not need to setup 2 networks.

All you need to do is turn off the existing DHCP server on your network.

You can easily set up dhcpd to do the work that your existing DHCP server did as well as support PXE clients.

Here is my dhcp.conf.

The PXE strings should be one long line not split over 2 .



# Sample configuration file for ISCD dhcpd
#
# Make changes to this file and copy it to /etc/dhcpd.conf
#
ddns-update-style none;

default-lease-time 432000;
max-lease-time 864000;

option subnet-mask 255.255.255.0;
option broadcast-address 172.31.158.255;
option routers 172.31.158.250;
option domain-name-servers 172.31.158.100;
option netbios-name-servers 172.31.158.100;
option domain-name "itsoapbox.com";
option root-path "172.31.158.240:/opt/ltsp/i386";
option log-servers 172.31.158.240;

shared-network WORKSTATIONS {
subnet 172.31.158.0 netmask 255.255.255.0 {
range 172.31.158.1 172.31.158.99;
}
}
group {
use-host-decl-names on;
host ws001 {
hardware ethernet 00:E0:18:D9:1A:02;
fixed-address 172.31.158.101;
filename "/lts/pxelinux.0";
option vendor-encapsulated-options 09:0f:80:00:0c:4e:65:74:77:6f:72:6b:20:62:6f:6f:74:0a:07:00:50:72:6f:6d:70:74:06:01:02:08:03:80:00:0 0:47:04:80:00:00:00:ff;
}
host ws002 {
hardware ethernet 00:0C:6E:2D:DE:BD;
fixed-address 172.31.158.102;
filename "/lts/pxelinux.0";
option vendor-encapsulated-options 09:0f:80:00:0c:4e:65:74:77:6f:72:6b:20:62:6f:6f:74:0a:07:00:50:72:6f:6d:70:74:06:01:02:08:03:80:00:0 0:47:04:80:00:00:00:ff;
}
host ws003 {
hardware ethernet 00:0C:6E:2D:DE:93;
fixed-address 172.31.158.103;
filename "/lts/pxelinux.0";
option vendor-encapsulated-options 09:0f:80:00:0c:4e:65:74:77:6f:72:6b:20:62:6f:6f:74:0a:07:00:50:72:6f:6d:70:74:06:01:02:08:03:80:00:0 0:47:04:80:00:00:00:ff;
}
host ws004 {
hardware ethernet 00:0C:6E:2D:DE:8F;
fixed-address 172.31.158.104;
filename "/lts/pxelinux.0";
option vendor-encapsulated-options 09:0f:80:00:0c:4e:65:74:77:6f:72:6b:20:62:6f:6f:74:0a:07:00:50:72:6f:6d:70:74:06:01:02:08:03:80:00:0 0:47:04:80:00:00:00:ff;
}
host ws005 {
hardware ethernet 00:0C:6E:2D:DF:9E;
fixed-address 172.31.158.105;
filename "/lts/pxelinux.0";
option vendor-encapsulated-options 09:0f:80:00:0c:4e:65:74:77:6f:72:6b:20:62:6f:6f:74:0a:07:00:50:72:6f:6d:70:74:06:01:02:08:03:80:00:0 0:47:04:80:00:00:00:ff;
}
}