Linux下配置DHCP中繼代理

假設一台計算機做軟路由，有三個網卡，連接3個不同的網段，192.168.1.1/24, 192.168.2.1/24,192.168.3.1/24;其中192.168.1.1/24這個網段有一個DHCP服務器，那怎麼樣設置可以使192.168.2.1/24和192.168.3.1/24這兩個網段分配IP呢？

首先得在dhcp.conf文件中添加超級作用域：

ddns-update-style interim;       ;指定DHCP支持的DNS動態更新為interim
   ignore client-updates;              ;指定不允許客戶機更新DNS記錄。
   shared-network xxxdhcp  {     ；超級作用域名為xxxdhcp
   option subnet-mask 255.255.255.0;
   option domain-name-servers  192.168.1.2,192.168.1.10,192.168.4.1;
  option broadcast-address 192.168.1.255;
  default-lease-time 86400;
  max-lease-time 172800;
     }

   subnet 192.168.1.0  netmask 255.255.255.0 {
    range 192.168.1.21 192.168.1.49;
    option routers 192.168.1.1;
     host pc1 {
       hardware ethernet MAC;
       fixed-address 192.168.1.20;
}
}

subnet 192.168.2.0  netmask 255.255.255.0 {
    range 192.168.2.21 192.168.2.49;
    option routers 192.168.2.1;
     host pc1 {
       hardware ethernet MAC;
       fixed-address 192.168.2.20;
}
}

subnet 192.168.3.0  netmask 255.255.255.0 {
    range 192.168.3.21 192.168.3.49;
    option routers 192.168.3.1;
     host pc1 {
       hardware ethernet MAC;
       fixed-address 192.168.3.20;
}
}

linux下的DHCP客戶端：/etc/sysconfig/network-scripts/ifcfg-eth0把BOOTPROTO="none"修改為BOOTPROTO="dhcp"

如果需要在系統啟動時自動引導啟動聯網，/etc/sysconfig/networking下的networking=yes。