dhcp options PXE boot

in CCNP
I am currently setting up a lab to boot a thin client from a debain server which will be located on a remote subnet.
So I figure how I would do this is have a DHCP relay but i'm a bit confused about the config.
should I find out what udp port PXE is using and use 'ip forward-protocol udp (port)
or use
ip dhcp pool thin-client-subnet
option 128 ip (debian server IP)
I won't have the server in front of me till tomorrow so I can't test between the two configs
So I figure how I would do this is have a DHCP relay but i'm a bit confused about the config.
should I find out what udp port PXE is using and use 'ip forward-protocol udp (port)
or use
ip dhcp pool thin-client-subnet
option 128 ip (debian server IP)
I won't have the server in front of me till tomorrow so I can't test between the two configs
What's another word for Thesaurus?
Comments
I'm not 100% how the server is set up yet, or if it's asking as a DHCP server aswell, I think it probably is.
if the debain box is a DHCP should I use the 'ip forward-protocol' on the relay
and if it's not use the 'option 128 (debian IP) on the DHCP server I have in IOS?
I have two routers with a serial connection between them. The debain box will be at one end and the thin client at the other.
So if I use the router connected to the debain box as a DHCP server I need to forward the protocol on the relay. But then on the DHCP server do I need to configure an option for PXE or should I use 2 x ip forward-protocol commands on the relay, one for the router(dhcp server) and one for the debian box?