DHCP中继原理理
当企业的内部⽹网络规模较⼤大时，通常被划分为多个不同的⼦⽹，⽹络内配置
了VLAN，VLAN能隔离⼴广播，而DHCP协议使⽤广播。DHCP服务器器在VLAN 100
中，就只有VLAN 100内的客户机能从DHCP服务器那里获取IP地址
DHCP服务器提供服务的方式主要有以下两种：
1、限定租期
2、租用
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主服务器：IP为192.168.200.115
[root@localhost ~]# iptables -F
[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# setenforce 0
[root@localhost ~]# yum -y install bind
[root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 192.168.200.115
nameserver 192.168.200.112
[root@localhost ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.200.115 ns1.crushlinux.com
192.168.200.112 ns2.crushlinux.com
[root@localhost ~]# cat /etc/named.conf 
[root@localhost ~]# cat /var/named/crushlinux.zheng
[root@localhost ~]# cat /var/named/crushlinux.fan
[root@localhost ~]# chown :named /var/named/crushlinux.*
[root@localhost ~]# named-checkconf -z /etc/named.conf
[root@localhost ~]# named-checkzone crushlinux.com /var/named/crushlinux.zheng
[root@localhost ~]# named-checkzone crushlinux.com /var/named/crushlinux.fan
[root@localhost ~]# systemctl restart named
======================================================================
从服务器：IP为192.168.200.112
[root@localhost ~]# yum -y install bind
[root@localhost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 192.168.200.115
nameserver 192.168.200.112
[root@localhost ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.200.115 ns1.crushlinux.com
192.168.200.112 ns2.crushlinux.com
[root@localhost ~]# cat /etc/named.conf
[root@localhost ~]# systemctl restart named
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windows客户机配置
测试：
