本文转账自http://www.itxinxi.net/blog/read.php/401.htm

vi /etc/iproute2/rt_tables

#
# reserved values
#
255     local
254     main
253     default
0       unspec
252     ct
251     cnc

#
# local
#
#1      inr.ruhep

ip route flush table ct
ip route add default via 电信网关IP dev 网卡号(比如:eth0) src 电信IP table ct
ip rule add from 电信IP table ct

ip route flush table cnc
ip route add default via 网通网关IP dev 网卡号(比如:eth1) src 网通IP table cnc
ip rule add from 网通IP table cnc

以上脚本  做成 .sh脚本后  增加到服务器启动项

查看路由
ip route

115.238.229.160/27 dev eth0  proto kernel  scope link  src 115.238.229.175
101.64.237.0/26 dev eth1  proto kernel  scope link  src 101.64.237.43
169.254.0.0/16 dev eth1  scope link
default via 115.238.229.161 dev eth0

查看网关：route

添加默认路由：

route add –net 0.0.0.0 netmask 0.0.0.0 gw 192.168.0.1

[root@localhost ~]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
101.226.249.192 *               255.255.255.240 U     0      0        0 eth1
210.51.47.128   *               255.255.255.128 U     0      0        0 eth0
default         101.226.249.193 0.0.0.0         UG    0      0        0 eth1
default         210.51.47.129   0.0.0.0         UG    0      0        0 eth0

查看机器所有路由表详细情况
ip route show table all

查看表252的路由情况
ip route list table 252

查看简洁路由表信息
ip route show all
ip route list

刷新路由表
ip route flush table 252