When doing a network installation of Linux, you can tell Linux to use the kickstart file using a range of options. Please check the Red Hat docs for your favorite options.
How do you do a network installation when booting from a CD (or PXE server)? Simple!
Insert CD 1, or mount that image through DRAC or iLO, at boot the machine. At the first command line of the boot CD type:
linux ks=http://server/path/kickstart_file.cfg url=http://server/path
linux ks=ftp://myserver/default-ks.cfg url=ftp://myserver/
where you have an ftp server running at hostname myserver and you have the CD contents (of ALL CDs) copied in the root of that ftp server. default-ks.cfg contains all your installation options.