1. Install all the required packages through yum
2. Create folder/directory and copy pxelinux.0
3. Open the xinetd settings to enable tftp server 
    vi /etc/xinetd.d/tftp
   # at line 14 change the parameter from yes to no.
        Disable=no 
4. Restart the service to apply the settings made
    systemctl restart xinetd 
5. Set the service to start with each subsequent system reboots
    systemctl enable xinetd
6. Open the file and configure edit the DHCP Server
    vi /etc/dhcp/dhcpd.conf
Allow booting;
Allow bootp;
authoritative;
### Subnet definition hostname kickstart server ###
ddns-update-style interim;
subnet 192.168.111.0 netmask 255.255.255.0 {
range dynamic-bootp 192.168.111.30 192.168.111.130;
option broadcast-address 192.168.111.255;
option routers 192.168.111.2;
filename "pxelinux.0";
next-server 192.168.111.80;
#use-host-decl-names on;
}
#### Client Node ###
host master01.kopi.com {
hardware ethernet 00:0C:29:33:9A:F2;
fixed-address 192.168.111.81;
option subnet-mask 255.255.255.0;
option routers 192.168.111.2;
option host-name "master01.kopi.com";
filename "pxelinux.0";
}
host master02.kopi.com {
hardware ethernet 00:0C:29:B0:74:AB;
fixed-address 192.168.111.82;
option subnet-mask 255.255.255.0;
option routers 192.168.111.2;
option host-name "master02.kopi.com";
filename "pxelinux.0";
}
host worker01.kopi.com {
hardware ethernet 00:0C:29:58:E8:B8;
fixed-address 192.168.111.83;
option subnet-mask 255.255.255.0;
option routers 192.168.111.2;
option host-name "worker01.kopi.com";
filename "pxelinux.0";
}
host worker02.kopi.com {
hardware ethernet 00:0C:29:CF:37:CE;
fixed-address 192.168.111.84;
option subnet-mask 255.255.255.0;
option routers 192.168.111.2;
option host-name "worker02.kopi.com";
filename "pxelinux.0";
}
host worker03.kopi.com {
hardware ethernet 00:0C:29:AE:A3:EF;
fixed-address 192.168.111.85;
option subnet-mask 255.255.255.0;
option routers 192.168.111.2;
option host-name "worker03.kopi.com";
filename "pxelinux.0";
}
7. Restart the service and make it permanent
    systemctl restart dhcpd 
    systemctl enable dhcpd 
8. Create folder/directory 
9. Insert your CentOS 7. DVD + Mount it to /mnt
    mount /dev/sr0 /mnt 
10. Check the contents to see if it is properly mounted
    ls -al /mnt/
11. copy all DVD the contents to the /var/www/html/centos7.9 directory & updates
createrepo /var/www/html/updates
    eject
12. Copy the vmlinuz and initrd.img files to the tftpboot directory
    cp /var/www/html/centos7.9/images/pxeboot/vmlinuz /var/lib/tftpboot/centos7 
    cp /var/www/html/centos7.9/images/pxeboot/initrd.img /var/lib/tftpboot/centos7
13. Copy the menu file
    cp /usr/share/syslinux/menu.c32 /var/lib/tftpboot/
14. Prepare the boot menu.
    vi /var/lib/tftpboot/pxelinux.cfg/default
default menu.c32
prompt 0
timeout 100
menu title === PXE-CentOS7.9-Boot Menu===
label 1
menu label ^ 1) CentOS 7.9.2009
kernel centos7/vmlinuz
append initrd=centos7/initrd.img ks=http://192.168.111.80/ks/ks.cfg
15. Prepare the httpd server
    vi /etc/hosts
       192.168.111.80     kickserver    kickserver.customer.com
     systemctl restart httpd 
    systemctl enable httpd
    vi /etc/selinux/config
     SELINUX=disable
 
reboot
after that you can login and run cli (pls, verify with a local repository "updates")
yum update
reboot
(pls, verify your booting with a new kernel version 3.10.0-1160.80.1.el7)
 
