linux_dhcp配置

转自：http://blog.chinaunix.net/uid-24929997-id-3056842.html
地方

一、修改dhcp服务器ip地址：

1）修改eth0地址：

vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
IPADDR=192.168.1.100
NETMASK=255.255.255.0
BOOTPROTO=static
HWADDR=........
ONBOOT=yes
TYPE=Ethernet

2）修改eth1地址

vim /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
IPADDR=192.168.2.100
NETMASK=255.255.255.0
BOOTPROTO=static
HWADDR=.........
service network restart  使修改的地址生效

二、yum安装dhcp

yum -y install dhcp

三、复制dhcpd配置文件的样本

cp /usr/share/doc/dhcp*/dhcpd.conf.sample /etc/dhcpd.conf

四、编辑配置文件

vim /etc/dhcpd.conf
ddns-update-style interim;
ignore client-updates;
subnet 192.168.0.0 netmask 255.255.255.0 {
# --- default gateway
        option routers                  192.168.0.1;
        option subnet-mask 255.255.255.0;
        option nis-domain "domain.org";
        option domain-name "domain.org"; #域名
        option domain-name-servers      192.168.1.1;
        option time-offset -18000; # Eastern Standard Time
# option ntp-servers              192.168.1.1;
# option netbios-name-servers     192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don

修改为

ddns-update-style interim; #dhcp服务器和dns服务器内部更新自动协商
ignore client-updates;
subnet 192.168.1.0 netmask 255.255.255.0 {
        option routers                  192.168.1.1; #网关
        option subnet-mask 255.255.255.0; #子网掩码
        option domain-name-servers      202.103.24.68,202.103.0.117; #DNS服务器地址
        option time-offset -18000; # Eastern Standard Time
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
#       option netbios-node-type 2;
        range dynamic-bootp 192.168.1.101 192.168.1.200;                   #地址池
        default-lease-time 21600;                                          #默认租约时间（秒）
        max-lease-time 43200;                #最大租约时间（秒）
        # we want the nameserver to appear at a fixed address
        host JTWD01-28 {
                next-server marvin.redhat.com;
                hardware ethernet 00:1E:90:17:CC:67;                       #根据主机网卡mac地址分配IP地址
                fixed-address 192.168.1.88;                                #分配的固定IP地址
        }
}
subnet 192.168.2.0 netmask 255.255.255.0 {
        option routers                  192.168.2.1;
        option subnet-mask              255.255.255.0;
        option domain-name-servers      202.103.24.68,202.103.0.117;
        option time-offset              -18000; # Eastern Standard Time
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
# option netbios-node-type 2;
        range dynamic-bootp 192.168.2.101 192.168.2.200;
        default-lease-time 21600;
        max-lease-time 43200;
}

五、应用不同的网络接口:

vim /etc/sysconfig/dhcpd
DHCPDARGS=eth0 // DHCPDARGS=eth1                      #仅在eth0上提供dhcp服务

六、开启dhcp服务：

service dhcpd start                                    #stop status restart

注：/var/lib/dhcpd/dhcpd.leases 中记录着DHCP服务器向DHCP客户机提供租用的每个IP地址的信息

七、DHCP中继代理
1）首先安装dhcpd服务（里面包含中继代理服务）
2）启用路由功能:

echo "1" > /proc/sys/net/ipv4/ip_forward

3）然后修改dhcrelay的配置文件：

vim  /etc/sysconfig/dhcrelay

加入以下内容：

INTERFACES="eth0 eth1"
DHCPSERVERS="192.168.1.2"

4）给dhcp服务器增加新网段的地址池
5）启动中继服务

service  dhcrelay  start

6）客户端测试