Linux环境网通电信双线自动切换教程

一、和要求：

线路:   内网百兆网络1:   eth0    192.168.1.1 100Mbit

      电信百兆光纤1:   eth1    222.88.1.1     gateway 222.88.1.2 100Mbit

      网通百兆光纤1 :   eth2    218.28.1.1     gateway 218.28.1.2 100Mbit

操作系统: Red Hat Enterprise AS 5


二、 网络要求：

业务需求: 一. 双线策略路由,网通IP走网通网关,电信IP走电信网关.

            二. 网内所有主机ARP绑定

            三. TC流量控制, 根据提供服务不同,走相应的策略.
     
三、具体步骤:

1. linux安装这里不多介绍,网上的很多.装完之后配置IP地址,满足上面的线路需求即可.(注:安装时尽量不要配置gateway,会和iproute2有冲突)

2.   打开内核IP转发机制:   echo "1" > /proc/sys/net/ipv4/ip_forward

3. SNAT地址转换:
iptables -t nat -A POSTROUTING -s 192.168.0.0/22 -o eth1 -j MASQUERADE
iptables -t nat -A POSTROUTING -s 192.168.0.0/22 -o eth2 -j MASQUERADE

本帖隐藏的内容需要回复才可以浏览4. 修改/etc/iproute2/ rt_table文件,建立路由表对应关系.具体文件格式如下:

# reserved values
#
255 local
254 main
253 default
0 unspec
100 shangdu
#
# local
#
#1   inr.ruhep

5.   配置电信默认路由添加到main表中:

ip route add 0/0 via 222.88.1.2   dev eth1 table main

6. 新建路由表table 100,配置网通默认路由添加到100表中:

ip route add 0/0 via 218.28.1.2 dev eth2 table 100
   
7. 在table 100的路由表中添加规则.(注:包含所有的网通IP段)
ip rule add to 58.16.0.0/16 table 100
ip rule add to 58.17.0.0/17 table 100
ip rule add to 58.17.128.0/17 table 100
ip rule add to 58.18.0.0/16 table 100
ip rule add to 58.19.0.0/16 table 100
ip rule add to 58.20.0.0/16 table 100
ip rule add to 58.21.0.0/16 table 100
ip rule add to 58.22.0.0/15 table 100
ip rule add to 58.240.0.0/15 table 100
ip rule add to 58.242.0.0/15 table 100
ip rule add to 58.244.0.0/15 table 100
ip rule add to 58.246.0.0/15 table 100
ip rule add to 58.248.0.0/13 table 100
ip rule add to 60.0.0.0/13 table 100
ip rule add to 60.8.0.0/15 table 100
ip rule add to 60.10.0.0/16 table 100
ip rule add to 60.11.0.0/16 table 100
ip rule add to 60.12.0.0/16 table 100
ip rule add to 60.13.0.0/18 table 100
ip rule add to 60.13.64.0/18 table 100
ip rule add to 60.13.128.0/17 table 100
ip rule add to 60.14.0.0/15 table 100
ip rule add to 60.16.0.0/13 table 100
ip rule add to 60.24.0.0/14 table 100
ip rule add to 60.28.0.0/15 table 100
ip rule add to 60.30.0.0/16 table 100
ip rule add to 60.31.0.0/16 table 100
ip rule add to 60.55.0.0/16 table 100
ip rule add to 60.208.0.0/13 table 100
ip rule add to 60.216.0.0/15 table 100
ip rule add to 60.218.0.0/15 table 100
ip rule add to 60.220.0.0/14 table 100
ip rule add to 61.48.0.0/14 table 100
ip rule add to 61.52.0.0/15 table 100
ip rule add to 61.54.0.0/16 table 100
ip rule add to 61.55.0.0/16 table 100
ip rule add to 61.133.0.0/17 table 100
ip rule add to 61.134.96.0/19 table 100
ip rule add to 61.134.128.0/18 table 100
ip rule add to 61.134.192.0/18 table 100
ip rule add to 61.135.0.0/16 table 100
ip rule add to 61.136.0.0/18 table 100
ip rule add to 61.136.64.0/18 table 100
ip rule add to 61.137.128.0/17 table 100
ip rule add to 61.138.0.0/18 table 100
ip rule add to 61.138.64.0/18 table 100
ip rule add to 61.138.128.0/18 table 100
ip rule add to 61.139.128.0/18 table 100
ip rule add to 61.148.0.0/15 table 100
ip rule add to 61.156.0.0/16 table 100
ip rule add to 61.158.0.0/17 table 100
ip rule add to 61.158.128.0/17 table 100
ip rule add to 61.159.0.0/18 table 100
ip rule add to 61.161.0.0/18 table 100
ip rule add to 61.161.128.0/17 table 100
ip rule add to 61.162.0.0/16 table 100
ip rule add to 61.163.0.0/16 table 100
ip rule add to 61.167.0.0/16 table 100
ip rule add to 61.168.0.0/16 table 100
ip rule add to 61.176.0.0/16 table 100
ip rule add to 61.179.0.0/16 table 100
ip rule add to 61.180.128.0/17 table 100
ip rule add to 61.181.0.0/16 table 100
ip rule add to 61.182.0.0/16 table 100
ip rule add to 61.189.0.0/17 table 100