linux服务器，设置双网卡双线ip后外网无法访问，一般传统方法设置双线路是电信路由表，联通走默认路由，这种方法不够智能，需要定期更新电信路由表，而且准确度不高，会出现访问电信地址从联通接口返回的问题。
使用iproute2高级功能，通过判断访问目的IP地址，然后从原网卡返回可以解决这个问题。
vi route.sh
#/bin/bash
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# flush ip rule for Repeat to add
ip rule flush
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# this is add the system default ip rule
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ip rule add from all lookup main prio 32766
ip rule add from all lookup default prio 32767
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ip route flush table cnc
ip route add default via 119.188.124.65 dev eth0 src 119.188.124.87 table cnc
ip rule add from 119.188.124.87 table cnc
ip route flush table tel
ip route add default via 218.98.33.129 dev eth1 src 218.98.33.188 table tel
ip rule add from 218.98.33.188 table tel
只主机网卡配置上只为eth0添加网关.
查看ip rule
[root@localhost ~]# ip rule list
0: from all lookup local
32764: from 218.98.33.188 lookup tel
32765: from 119.188.124.87 lookup cnc
32766: from all lookup main
32767: from all lookup default
