Need help with DHCP Server (dhcpd.conf)

I am new to DHCP configuration and I've done some research but I can't seem to find anything that will help me.

I'm trying to configure the DHCP server in such a way that the same machine boots differently depending on its subnet.

That is:

• If computer-A on Subnet1 then boot using bootfile1
• If computer-A on Subnet2 then boot using bootfile2
• If computer-B on Subnet1 then boot using bootfile3
• If computer-B on Subnet2 then boot using bootfile3

Where computer-A and computer-B are not necessarily desktop computer.

My requirement is too define the computer using the vendor-class-identifier option.

I can create a class to define the machine vendor, but how do I specify the subnet? Is it possible to define the computer (using option vendor-class-identifier) in the subnet declaration without impacting computers from another manufacturer?

Any help is greatly appreciated.

Bassam