本次环境实验环境为VM Virtualbox

拓扑图：

我们可以使用VM VirtualBox模拟两个网络

用到3台CentOS5.5,1台Windows 2008

其中DHCP中继服务器为CentOS模拟路由器

详细情况：

名称：DHCP服务器

IPv4：192.168.5.10

FQDN：dhcp.abc.com

网卡：Host-Only

名称：DHCP中继

IPv4：192.168.5.1

IPv4：192.168.6.1

FQDN：relay.abc.com

网卡：Host-Only

网卡：内部网卡

名称：Linux客户机

IPv4：DHCP／BOOTP

FQDN：client.abc.com

网卡：Host-Only

名称：Win08TEST

IPv4：DHCP／BOOTP

FQDN：08.abc.com

网卡：网卡：内部网卡

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注意：实验除DHCP中继服务器尽量关闭iptables ,和SeLinux

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第一步：安装配置DHCP服务器

yum install dhcp -y

cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample /etc/dhcpd.conf

vim /etc/dhcpd.conf

ddns-update-style interim;
ignore client-updates;
option domain-name "zcm.com";
option domain-name-servers 8.8.8.8;

shared-network abc {
default-lease-time 21600;
max-lease-time 43200;

subnet 192.168.6.0 netmask 255.255.255.0 {

        option routers                  192.168.6.1;
        option subnet-mask              255.255.255.0;
        option time-offset              -18000; # Eastern Standard Time
        range dynamic-bootp 192.168.6.128 192.168.6.138;


}

subnet 192.168.5.0 netmask 255.255.255.0 {

        option routers                  192.168.5.1;
        option subnet-mask              255.255.255.0;
        option time-offset              -18000; # Eastern Standard Time
        range dynamic-bootp 192.168.5.128 192.168.5.138;


}
}
}

/etc/init.d/dhcpd configtest

显示 Syntax：OK 则没有问题

/etc/init.d/dhcpd restart

重启DHCP服务器

chkconfig dhcpd on

设置DHCP服务器开机启动

setenforce 0

临时关闭SELINUX

第二步：配置DHCP中继服务器

yum install dhcp -y

配置DHCP中继

dhrelay 192.168.5.10

或者编辑/etc/sysconfig/dhcrelay

INTERFACES="eth0 eth1"
DHCPSERVERS="192.168.5.10"

查看dhcp中继状态

/etc/init.d/dhcrelay status

清除防火墙配置

iptables -F

清除防火墙NAT配置

iptables -t nat -F

临时关闭SELinux

setenforce 0

第三步：使用Linux客户机测试

dhclient -r

重置动态IP

dhclient eth0

重新获取IP

第四步：使用windows测试

ipconfig/all

查看所有网卡信息

ipconfig /release

清除DHCP地址

ipconfig /renew

重新获取DHCP地址

第四步：配置地址保留

查看Win/LinuxMAC地址

继续在DHCP服务器中编辑：

vim /etc/dhcpd.conf

ddns-update-style interim;
ignore client-updates;
option domain-name "zcm.com";
option domain-name-servers 8.8.8.8;

shared-network linsrv {
default-lease-time 21600;
max-lease-time 43200;

subnet 192.168.6.0 netmask 255.255.255.0 {

        option routers                  192.168.6.1;
        option subnet-mask              255.255.255.0;
        option time-offset              -18000; # Eastern Standard Time
        range dynamic-bootp 192.168.6.128 192.168.6.138;

        host ns {
                next-server win088.com;
                hardware ethernet 08:00:27:40:86:AD;
                fixed-address 192.168.6.133;
}
}

subnet 192.168.5.0 netmask 255.255.255.0 {

        option routers                  192.168.5.1;
        option subnet-mask              255.255.255.0;
        option time-offset              -18000; # Eastern Standard Time
        range dynamic-bootp 192.168.5.128 192.168.5.138;
host winsrv {
                next-server win08.abc.com;
                hardware ethernet 08:00:27:47:BF:C6;
                fixed-address 192.168.5.133;
}
}
}