Centos8上搭建dhcp服务器

Centos8上搭建dhcp服务器

首先我的环境是在本地的VMware虚拟机，所以先将VMware中的dhcp服务关闭

关闭防火墙，关闭selinux这些必须关闭：

systemctl stop firewalld
setenforce 0

在centos8上安装dhcp-server端

[root@Centos8 ~]#yum install dhcp-server.x86_64

查看安装的包和文件

[root@Centos8 ~]#rpm -ql dhcp-server /etc/NetworkManager/etc/NetworkManager/dispatcher.d/etc/NetworkManager/dispatcher.d/12-dhcpd/etc/dhcp                                                      #客户端/etc/dhcp/dhcpd.conf                                    #dhcp配置文件（空文件）/etc/dhcp/dhcpd6.conf                                  #ipv6配置文件/etc/openldap/schema/etc/openldap/schema/dhcp.schema/etc/sysconfig/dhcpd/usr/bin/omshell/usr/lib/.build-id/usr/lib/.build-id/61/usr/lib/.build-id/61/6771248bc042fe96877bd9496ad99a4a4817fc/usr/lib/.build-id/e0/usr/lib/.build-id/e0/17e374d1a55a7254398988114fdd6a0bd63df3/usr/lib/systemd/system/dhcpd.service/usr/lib/systemd/system/dhcpd6.service/usr/sbin/dhcpd                                               #服务器端/usr/share/doc/dhcp-server/usr/share/doc/dhcp-server/dhcp-lease-list.pl/usr/share/doc/dhcp-server/dhcpd.conf.example           #配置文件范例/usr/share/doc/dhcp-server/dhcpd6.conf.example/usr/share/doc/dhcp-server/ldap/usr/share/doc/dhcp-server/ldap/README.ldap/usr/share/doc/dhcp-server/ldap/dhcp.schema/usr/share/doc/dhcp-server/ldap/dhcpd-conf-to-ldap/usr/share/man/man1/omshell.1.gz/usr/share/man/man5/dhcpd.conf.5.gz/usr/share/man/man5/dhcpd.leases.5.gz/usr/share/man/man8/dhcpd.8.gz/var/lib/dhcpd/var/lib/dhcpd/dhcpd.leases                             #地址分配记录/var/lib/dhcpd/dhcpd6.leases[root@Centos8 ~]#

然后启动dhcp服务

[root@Centos8 ~]#systemctl start dhcpd.service

发现启动报错，是因为dhcp如果没有配置本网段的dhcp规则是拒绝启动的。
查看配置文件：

[root@Centos8 ~]#vim /etc/dhcp/dhcpd.conf## DHCP Server Configuration file.#   see /usr/share/doc/dhcp-server/dhcpd.conf.example#   see dhcpd.conf(5) man page#

dhcp默认配置文件是空的，但是它说了看/usr/share/doc/dhcp-server/dhcpd.conf.example这个文件，这个是dhcp配置的一些范例。

[root@Centos8 ~]#cp /usr/share/doc/dhcp-server/dhcpd.conf.example /etc/dhcp/dhcpd.conf

直接替换配置文件，再次查看：

[root@Centos8 ~]#vim /etc/dhcp/dhcpd.conf# dhcpd.conf#其中全局语句块和subnet语句块均可使配置生效，subnet语句块优先级高于全局语句块：#全局语句块:# option definitions common to all supported networks...#指定获取主机域后缀：option domain-name "wj02.com";#指定DNS，可选option domain-name-servers 180.76.76.76, 119.29.29.29;#ip的租期，单位：秒default-lease-time 86400;    #默认是600s，客户端会在租期的一半也就是300s后进行续租，组曲太短会占用大量的网络带宽，建议改时间长一点。这里修改为86400s，一天。#最大租期时间max-lease-time 100000;...log-facility local7;...#subnet配置#指定网段subnet 192.168.38.0 netmask 255.255.255.0 {    #指定分配的ip范围，可以跳过一些地址    range 192.168.38.10 192.168.38.120;    range 192.168.38.150 192.168.38.254;    #指定网关    option routers 192.168.38.2;}#为一个mac地址分配一个固定的ip，效果等同于静态获取host test {  hardware ethernet 00:0c:29:58:4f:12;  fixed-address 192.168.39.102;}#为00:0c:29:58:4f:12这个mac地址固定的分配192.168.39.120这个地址......

dhcp还有语法检查功能：

dhcpd -t -cf /etc/dhcp/dhcpd.conf

当然如果语法不对，启动也会报错的，这个其实不重要。
配置文件修改完毕后，重新启动dhcp服务

[root@Centos8 ~]#systemctl start dhcpd

启动成功。
在客户端获取ip

dhclient -d

因为配置文件里我绑定了mac地址，所以这个服务器应该分配到192.168.38.102这个ip

至此，dhcp服务器搭建成功。