实验环境 1台Centos7.6的虚拟机 ip: 192.168.148.17/24 配置PXE环境；新建一台虚拟机作为测试机

本次实验采用 dnsmasq作为dhcp、tftp服务器; vsftpd 提供安装源

# 关闭防火墙
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# systemctl disable firewalld
#syslinux 提供pxe启动的引导文件
[root@localhost ~]# yum -y install dnsmasq vsftpd syslinux
[root@localhost ~]# mkdir /var/ftp/pub/centos7
[root@localhost ~]# systemctl enable dnsmasq vsftpd 
[root@localhost ~]# systemctl start  vsftpd 
[root@localhost ~]# mkdir /var/ftp/pub/centos7
[root@localhost ~]# mount /dev/sr0 /var/ftp/pub/centos7/
# 创建tftp服务目录
[root@localhost ~]# mkdir /var/lib/dnsmasq/tftpboot/
[root@localhost ~]# cd /var/lib/dnsmasq/tftpboot/
[root@localhost tftpboot]# cp /usr/share/syslinux/{menu.c32,gpxelinux.0} .
[root@localhost tftpboot]# mkdir pxelinux.cfg
[root@localhost tftpboot]# cp /var/ftp/pub/centos7/isolinux/isolinux.cfg pxelinux.cfg/default
# 编辑default文件最终内容如下 Gpxe除了支持传统的tftp还支持ftp,http方式下载文件
default menu.c32
timeout 600
menu title CentOS 7

label linux
  menu label ^Install CentOS 7
  kernel ftp://192.168.148.17/pub/centos7/isolinux/vmlinuz
  append initrd=ftp://192.168.148.17/pub/centos7/isolinux/initrd.img  inst.repo=ftp://192.168.148.17/pub/centos7/

label local
  menu label Boot from ^local drive
  menu default
  localboot 0xffff

# 在/etc/dnsmasq.d/ 创建pxe.conf  ;指定 dhcp地址池的范围，启用tftp功能,指定tftp服务器地址和引导文件；文件内容如下:
[root@localhost ~]# cat /etc/dnsmasq.d/pxe.conf 
dhcp-range=192.168.148.50,192.168.148.100,255.255.255.0,12h
enable-tftp
dhcp-boot=/var/lib/dnsmasq/tftpboot/gpxelinux.0,192.168.148.17

[root@localhost ~]# systemctl start dnsmasq
# 检测ipv4 监听的udp端口
[root@localhost ~]# ss -4  -unl
State      Recv-Q Send-Q                      Local Address:Port                                     Peer Address:Port              
UNCONN     0      0                                       *:53                                                  *:*                  
UNCONN     0      0                                       *:67                                                  *:*                          
UNCONN     0      0                                       *:69                                                  *:* 

# 所需端口都正常开启
# 如果需要开启防火墙 需要添加对应的服务
[root@localhost ~]# systemctl enable firewalld
[root@localhost ~]# systemctl start firewalld
[root@localhost ~]# firewall-cmd --list-all
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: eth0
  sources: 
  services: ssh dhcpv6-client
  ports: 
  protocols: 

[root@localhost ~]#  firewall-cmd  --permanent --add-service=ftp
[root@localhost ~]#  firewall-cmd  --permanent --add-service=tftp
[root@localhost ~]#  firewall-cmd  --permanent --add-service=dhcp
[root@localhost ~]# firewall-cmd --reload
[root@localhost ~]# firewall-cmd --list-all
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: eth0 eth1
  sources: 
  services: ssh dhcpv6-client dhcp ftp tftp

启动另一台新的虚拟默认从网络启动进行系统安装