centos5.5 双网卡设置，并配置dhcp

我的物理拓扑图如下：我要做的是把frontend作为主机，配置DHCP Server 为子网自动分配IP。

1）vim /etc/sysconfig/network-scripts/ifcfg-eth0 ，  形如
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:15:17:9d:0f:51
ONBOOT=yes
NETMASK=255.255.255.128
IPADDR=219.224.169.157
GATEWAY=219.224.169.129
TYPE=Ethernet

2）vim /etc/sysconfig/network-scripts/ifcfg-eth1 ，  形如
DEVICE=eth1
BOOTPROTO=none
HWADDR=00:15:17:9d:0f:51
ONBOOT=yes
NETMASK=255.255.255.0
IPADDR=192.168.1.1
TYPE=Ethernet

（注意，内网不用设置GateWay）

3）service network restart

4） vi /etc/dhcpd.conf 

 ddns-update-style interim;     #配置使用过渡性 DHCP-DNS互动更新模式。
 ignore client-updates;         #忽略客户端更新


 subnet 192.168.1.0 netmask 255.255.255.0 {

         option routers                  192.168.1.1;        #路由器地址
         option subnet-mask              255.255.255.0;      #子网掩码选项

         option nis-domain               "xfbaydhcp.com";
         option domain-name              "xfbaydhcp.com";     #域名
         option domain-name-servers      202.102.152.3;       #DNS地址

         option time-offset              -18000; # Eastern Standard Time

         range dynamic-bootp 192.168.1.100 192.168.1.200;       #租用IP地址的范围
         default-lease-time 21600;    #缺省租约时间
         max-lease-time 43200;        #最大租约时间

         # we want the nameserver to appear at a fixed address
         host ns {
                 next-server marvin.redhat.com;
                 hardware ethernet 12:34:56:78:AB:CD;
                 fixed-address 207.175.42.254;
         }
 }

5） vim /etc/sysconfig/dhcpd 

      DHCPDARGS=eth1

6）service dhcpd restart