The steps shown in this section configure the built-in NFS and TFTP servers. The next section demonstrates how to install and configure the DHCP server. In this example, the directory which will contain the files used by PXE users is /b/tftpboot/FreeBSD/install. It is important that this directory exists and that the same directory name is set in both /etc/inetd.conf and /usr/local/etc/dhcpd.conf.

When booting from an NFS root volume, /etc/rc detects the NFS boot and runs /etc/rc.initdiskless. In this case, /etc and /var need to be memory backed file systems so that these directories are writable but the NFS root directory is read-only:

# chroot ${NFSROOTDIR}
# mkdir -p conf/base
# tar -c -v -f conf/base/etc.cpio.gz --format cpio --gzip etc
# tar -c -v -f conf/base/var.cpio.gz --format cpio --gzip var

When the system boots, memory file systems for /etc and /var will be created and mounted and the contents of the cpio.gz files will be copied into them. By default, these file systems have a maximum capacity of 5 megabytes. If your archives do not fit, which is usually the case for /var when binary packages have been installed, request a larger size by putting the number of 512 byte sectors needed (e.g., 5 megabytes is 10240 sectors) in ${NFSROOTDIR}/conf/base/etc/md_size and ${NFSROOTDIR}/conf/base/var/md_size files for /etc and /var file systems respectively.

The DHCP server does not need to be the same machine as the TFTP and NFS server, but it needs to be accessible in the network.

DHCP is not part of the FreeBSD base system but can be installed using the net/isc-dhcp43-server port or package.

Once installed, edit the configuration file, /usr/local/etc/dhcpd.conf. Configure the next-server, filename, and root-path settings as seen in this example:

subnet 192.168.0.0 netmask 255.255.255.0 {
   range 192.168.0.2 192.168.0.3 ;
   option subnet-mask 255.255.255.0 ;
   option routers 192.168.0.1 ;
   option broadcast-address 192.168.0.255 ;
   option domain-name-servers 192.168.35.35, 192.168.35.36 ;
   option domain-name "example.com";

   # IP address of TFTP server
   next-server 192.168.0.1 ;

   # path of boot loader obtained via tftp
   filename "FreeBSD/install/boot/pxeboot" ;

   # pxeboot boot loader will try to NFS mount this directory for root FS
   option root-path "192.168.0.1:/b/tftpboot/FreeBSD/install/" ;

}

The next-server directive is used to specify the IP address of the TFTP server.

The filename directive defines the path to /boot/pxeboot. A relative filename is used, meaning that /b/tftpboot is not included in the path.

The root-path option defines the path to the NFS root file system.

Once the edits are saved, enable DHCP at boot time by adding the following line to /etc/rc.conf:

dhcpd_enable="YES"

Then start the DHCP service:

# service isc-dhcpd start

Once all of the services are configured and started, PXE clients should be able to automatically load FreeBSD over the network. If a particular client is unable to connect, when that client machine boots up, enter the BIOS configuration menu and confirm that it is set to boot from the network.

This section describes some troubleshooting tips for isolating the source of the configuration problem should no clients be able to PXE boot.