server2的配置

ifconfig eth0 172.17.17.2 netmask 255.255.255.0 #设置ip地址
route add default gw 172.17.17.1  #设置默认网关
yum install dhcp-*    #安装dhcp服务


cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf  拷贝模板文件到etc下

vim /etc/dhcpd.conf   编辑配置文件
ddns-update-style none;
ignore client-updates;       
default-lease-time 12000;    默认的租约时间
max-lease-time 24000;         最大租约时间

subnet 172.17.17.0 netmask 255.255.255.0 {   

        option routers                  172.17.17.1;#默认路由
        option subnet-mask              255.255.255.0;#子网掩码
        range dynamic-bootp 172.17.17.100 172.17.17.200;#地址池
        host print {     #绑定地址
                hardware ethernet 12:34:56:78:AB:CD;
                fixed-address 172.17.17.101;
        }
}
subnet 192.168.1.0 netmask 255.255.255.0 { 

        option routers                  192.168.1.1;
        option subnet-mask              255.255.255.0;
        range dynamic-bootp 192.168.1.100 192.168.1.200;
}
subnet 192.168.2.0 netmask 255.255.255.0 {  

        option routers                  192.168.2.1;
        option subnet-mask              255.255.255.0;
        range dynamic-bootp 192.168.2.100 192.168.2.200;
}


/etc/init.d/dhcpd start     启动dhcp服务


dhcp中继代理server1的配置
yum install dhcp-*    #安装dhcp服务

 vim /etc/sysconfig/dhcrelay       配置中继配置文件

 
INTERFACES="eth0 eth1 eth2"  指定通过那个网络接口将客户端请求传递给服务器
DHCPSERVERS="172.17.17.2"    指定dhcp服务器到ip地址

vim /etc/syslog.conf
echo 1 >/proc/sys/net/ipv4/ip_forward   开启网卡转发功能

service dhcrelay start    启动中继服务


客户端测试
linux的主机利用dhclient 设备名称   获取IP地址
  dhclient -r      释放IP地址
windows的主机设网卡为自动获取