dhcpd setting for booting clients from a 4.2 server and a 5 server

[Krsnendu dasa]

I have an Edubuntu virtual server running under VMware server running
on K12LTSP 6.
K12 works fine. I have tested Edubuntu also by turning off dhcpd on
K12. That works too.
Now what I would like is that all clients continue to boot from K12
and only one or two (one virtual and one physical client) boot from
Edubuntu for testing.

What settings do I need to put in the dhcpd-k12ltsp.conf file to make
this work. Do I have to change the /etc/ltsp/dhcpd.conf file in any
way? Should dhcp be enabled on edubuntu or not?

Any tips would be greatly appreciated. I think LTSP 5 is very exciting
and I want to keep up to speed with it.

Thanks.
Krsnendu dasa