Here is how to set up a Mac, running OS X Client 10.5 or later, as a PXE boot server. We will configure OS X’s built-in DHCP, TFTP, and NFS servers, start the servers, and put the client boot files in place. (The NFS server may be optional, depending on the operating system we are booting.)

You’ll need the Mac, a PXE-capable PC, and an ethernet cable. Some steps will require being logged in as an administrator on the Mac.

We’ll boot Debian Live on the client PC as an example. We’ll show a regular setup with NFS, an alternate setup without NFS, and how to uninstall.

Regular setup (with NFS):

Connect the Mac and the client PC with the ethernet cable.

On the Mac, in System Preferences > Network, click “Ethernet” and enter the following settings:

Configure IPv4: Manually
IP Address: 192.168.1.1
Subnet Mask: 255.255.255.0
(All others can be left blank)

Note the status may read “Cable Unplugge …

Source: Mac OSX Hints