01.环境准备
操作系统：
[root@localhost ~]# cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)
[root@localhost ~]# ip a |grep ens33
ens33: 192.168.1.50/24
分区(小编这里使用虚拟机，物理内存划分了4G，根分区划分了100G)：
[root@localhost ~]# free -m
total used free shared buff/cache available
Mem: 3932 224 3345 11 361 3429
Swap: 8191 0 8191
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 91G 4.9G 87G 6% /
02.防火墙和Selinux设置
[root@localhost ~]# firewall-cmd --get-active-zones
public
[root@localhost ~]# firewall-cmd --set-default-zone=trusted //设置默认接口区域
success //立即生效无需重启
永久关闭selinux
vi /etc/selinux/config
修改enforcing为disabled
or
使用sed //sed用法请自行百度
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
setenforce 0 //临时关闭selinux
03.配置yum源，安装配置DHCP服务
3.1.配置yum源
[root@localhost ~]# mount /dev/cdrom /mnt
mount: /dev/sr0 is write-protected, mounting read-only
[root@localhost ~]# cd /etc/yum.repos.d
[root@localhost yum.repos.d]# mkdir bk
[root@localhost yum.repos.d]# mv *.repo bk/
[root@localhost yum.repos.d]# echo "[EL]" >> /etc/yum.repos.d/centos.repo
[root@localhost yum.repos.d]# echo "name =Linux 7.x DVD" >> /etc/yum.repos.d/centos.repo
[root@localhost yum.repos.d]# echo "baseurl=file:///mnt/" >> /etc/yum.repos.d/centos.repo
[root@localhost yum.repos.d]# echo "enabled=1" >> /etc/yum.repos.d/centos.repo
[root@localhost yum.repos.d]# echo "gpgcheck=0" >> /etc/yum.repos.d/centos.repo
[root@localhost yum.repos.d]# cat /etc/yum.repos.d/centos.repo
[EL]
name =Linux 7.x DVD
baseurl=file:///mnt/
enabled=1
gpgcheck=0
[root@localhost yum.repos.d]# yum repolist
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
EL | 3.6 kB 00:00:00
(1/2): EL/group_gz | 166 kB 00:00:00
(2/2): EL/primary_db | 3.1 MB 00:00:00
repo id repo name status
EL Linux 7.x DVD 4,021
repolist: 4,021
3.2.安装配置DHCP服务
[root@PXE ~]# yum install dhcp # 安装dhcp server
[root@PXE ~]# rpm -ql dhcp
/etc/dhcp
/etc/dhcp/dhcpd.conf # dhcpd配置文件
/etc/rc.d/init.d/dhcpd # dhcpd启动文件
/usr/sbin/dhcpd # 启动脚本配置文件
[root@PXE pxelinux.cfg]# vi /etc/dhcp/dhcpd.conf # 调整配置文件
# dhcpd.conf
#
option domain-name "itwish.cn";
option domain-name-servers 192.168.4.150 ;
default-lease-time 600;
max-lease-time 7200;
log-facility local7;
subnet 192.168.1.0 netmask 255.255.255.224 {
range 192.168.1.10 192.168.1.20;
option routers 192.168.1.250;
next-server 192.168.1.50; # 注：添加 tftp服务器地址
filename="pxelinux.0"; #注：告诉TFTP目录下的bootstarp文件
}
#注：配置文件中以";" 号结尾 ，且需添加next-server 和filename 项
启动dhcp并验证dhcpd进程是否处于监听状态：
ps aux | grep dhcpd # 验证dhcpd 启动
dhcpd 14087 0.0 0.1 48324 3572 ? Ss 03:13 0:00 /usr/sbin/dhcpd -user dhcpd -group dhcpd
root 14108 0.0 0.0 103272 840 pts/0 S+ 03:14 0:00 grep dhcpd
[root@PXE ~]# ss -tunl | grep 67
udp UNCONN 0 0 *:67 *:*
=======报错信息======================
[root@localhost dhcp]# journalctl -xe
No subnet declaration for ens33 (192.168.1.50).
Not configured to listen on any interfaces!
=======百度答案======================
# cat /etc/sysconfig/dhcpd
DHCPDARGS=ens33
#cp /usr/lib/systemd/system/dhcpd.service /etc/systemd/system/
[root@myserver tftpboot]# dhcpd -cf /etc/dhcpd.conf ens33
