Example:

電信IP:1.1.1.2　　Gateway:1.1.1.1

聯通IP:2.2.2.2　　Gateway:2.2.2.1

移動IP:3.3.3.2　　Gateway:3.3.3.1

1. 配置路由表字段
   

   vim /etc/iproute2/rt_tables
   
   #
   # reserved values
   #
   
   255        local
   254        main
   253        default
   0        unspec
   
   #
   # local
   #
   #1        inr.ruhep
   
   252        dx
   251        lt
   250        yd
    
   

2. 編寫路由指令碼
   

   vim route.sh
   
   #!/bin/env sh
   ip route flush table dx
   ip rule add from 1.1.1.2 table dx
   ip route add default via 1.1.1.1 dev eth0 src 1.1.1.2 table dx
   
   ip route flush table lt
   ip rule add from 2.2.2.2 table lt
   ip route add 0.0.0.0/0 via 2.2.2.1 dev eth1 src 2.2.2.2 table lt
   
   ip route flush table yd
   ip rule add from 
    
   3.3.3.2 table yd
   ip route add 0.0.0.0/0 via 3.3.3.1 dev eth2 src 3.3.3.2 table yd
   

3. 新增執行許可權
   

   chmod +x route.sh /etc/rc.d/rc.local

4. 新增開機啟動項
   

   echo "/root/route.sh" >> /etc/rc.d/rc.local

5. ip route flush table 100
   ip rule add from 1.1.1.2 table 100
   ip route add default via 1.1.1.1 dev em1 src 1.1.1.2 table 100
    
    prio 50
   
   ip route flush table 200
   ip rule add from 2.2.2.2 table 200
   ip route add default via 2.2.2.1 dev em2 src 2.2.2.2 table 200 prio 50