Install PXE Server on RHEL 8 / CentOS 8

A Preboot eXecution Environment server offers the needed resources to clients that were configured to boot from one of its network devices instead of booting from the classic mass storage options (SSD/HDD/DVD).

For this setup we will install the following packages:

• DNSMASQ – a light DNS Forwarder that support DNS and DHCP services with support for PXE and TFTP
• Syslinux – a linux boot loader for networking booting
• TFTP Server – a server which allow images to be downloaded via network
• VSFTPD Server – host for the locally mounted mirrored DVD images

Step 1: Setup DNSMASQ Server

# dnf install dnsmasq

Once it is installed we will find default configuration file under /etc/dnsmasq.conf. Let’s change it according our network settings.

interface=enp0s3,lo
#bind-interfaces
domain=0x01
# DHCP range-leases
dhcp-range= enp0s3,10.0.0.3,10.0.0.254,255.255.255.0,1h
# PXE
dhcp-boot=pxelinux.0,pxeserver,10.0.0.2
# Gateway
dhcp-option=3,10.0.0.1
# DNS
dhcp-option=6,10.0.0.1, 1.1.1.1
server=1.1.1.1
# Broadcast Address
dhcp-option=28,10.0.0.255
# NTP Server
dhcp-option=42,0.0.0.0

pxe-prompt="Press F8 for menu.", 60
pxe-service=x86PC, "Install CentOS 8 from PXE server", pxelinux
enable-tftp
tftp-root=/var/lib/tftpboot

Config lines that we need to change are:

• interface – network interfaces of the server to listen and provide service
• bind-interfaces – uncomment to bind interface to the given network card
• domain – replace with your domain
• dhcp-range – change with your network range
• dhcp-boot – replace with your network interface IP
• dhcp-option=3,192.168.1.1 – replace with your network Gateway
• dhcp-option=6,92.168.1.1 – replace with your DNS Server
• server=8.8.4.4 – add your DNS forwarders IPs
• dhcp-option=28,10.0.0.255 – replace with your network broadcast IP
• dhcp-option=42,0.0.0.0 - add your network time servers (0.0.0.0 is for self-reference)
• pxe-prompt – keep it as default
• pxe=service – use x86PC for 32-bit/64-bit architectures and add a menu description prompt order
• enable-tftp – enables built-in TFTP server
• tftp-root – add network booting files location /var/lib/tftpboot

Step 2: Setup SYSLINUX

# dnf install syslinux

Bootloaders are installed under /usr/share/syslinux

Step 3: Install TFTP-Server and Copy SYSLINUX Bootloaders

# dnf install tftp-server
# cp -r /usr/share/syslinux/* /var/lib/tftpboot

Step 4: Setup PXE Server

PXE Server reads configurations from specific files found in pxelinux.cfg. Create pxelinux.cfg directory and create default with the following commands.

# mkdir /var/lib/tftpboot/pxelinux.cfg
# touch /var/lib/tftpboot/pxelinux.cfg/default

Now let’s edit PXE default configuration file with our installation options. The following config is an example file that can be used.

default menu.c32
prompt 0
timeout 300
ONTIMEOUT local

menu title ########## PXE Boot Menu ##########

label 1
menu label ^1) Install CentOS 8 x64 (Local Repo)
kernel centos8/vmlinuz
append initrd=centos8/initrd.img method=ftp://10.0.0.2/pub devfs=nomount

label 2
menu label ^2) Install CentOS 8 x64 (Remote Repo)
kernel centos8/vmlinuz
append initrd=centos8/initrd.img method=http://mirror.centos.org/centos/8/BaseOS/x86_64/os/ devfs=nomount ip=dhcp

label 3
menu label ^3) Install CentOS 8 x64 (Local Repo using VNC)
kernel centos8/vmlinuz
append  initrd=centos8/initrd.img method=ftp://10.0.0.2/pub devfs=nomount inst.vnc inst.vncpassword=password

label 4
menu label ^4) Boot from local drive

Step 5: Add CentOS 8 Image to PXE Server

We need to download CentOS 8 DVD ISO image locally using wget and then mount it. Then we need to create a centos8 directory and copy bootable kernel and initrd images.

# wget http://mirrors.primetelecom.ro/centos/8.2.2004/isos/x86_64/CentOS-8.2.2004-x86_64-dvd1.iso
# mount -o loop CentOS-8.2.2004-x86_64-dvd1.iso /mnt
# mkdir /var/lib/tftpboot/centos8 
# cp /mnt/images/pxeboot/vmlinuz /var/lib/tftpboot/centos8 
# cp /mnt/images/pxeboot/initrd.img /var/lib/tftpboot/centos8

Step 6: Create CentOS 8 Local Mirror

Now we will install Vsftpd server and copy CentOS 8 DVD content to FTP directory /var/ftp/pub

# dnf install vsftpd
# cp -r /mnt/*  /var/ftp/pub/ 
# chmod -R 755 /var/ftp/pub

Now we can start, enable, and verify the status of DNSMASQ and VSFTPD servers

# systemctl start dnsmasq
# systemctl status dnsmasq
# systemctl start vsftpd
# systemctl status vsftpd
# systemctl enable dnsmasq
# systemctl enable vsftpd

That’s all for setting up a basic PXE Server on CentOS/RHEL 8.

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