CentOS双网卡配置默认路由

CentOS使用双网卡时，如果要指定其中一个网卡的网关作为默认路由，不能直接用route命令进行修改，或者只是删除其中一个默认路由。例如：

[Expert@sec-cpsc-8001sz:0]# ifconfig
eth0        Link encap:Ethernet  HWaddr 00:50:56:A6:4F:9A  
            inet addr:99.1.1.1  Bcast:99.1.16.255  Mask:255.255.255.0
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:264636824 errors:0 dropped:0 overruns:0 frame:0
            TX packets:1630865 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000 
            RX bytes:24486306913 (22.8 GiB)  TX bytes:2105592006 (1.9 GiB)

eth1        Link encap:Ethernet  HWaddr 00:50:56:A6:7E:F4  
            inet addr:192.168.127.8  Bcast:192.168.127.8  Mask:255.255.255.255
            UP BROADCAST MULTICAST  MTU:1500  Metric:1
            RX packets:0 errors:0 dropped:0 overruns:0 frame:0
            TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000 
            RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

lo          Link encap:Local Loopback  
            inet addr:127.0.0.1  Mask:255.0.0.0
            UP LOOPBACK RUNNING  MTU:16436  Metric:1
            RX packets:132847578 errors:0 dropped:0 overruns:0 frame:0
            TX packets:132847578 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:0 
            RX bytes:51965842204 (48.3 GiB)  TX bytes:51965842204 (48.3 GiB)

有99.1.1.1和192.168.127.8两个IP。如果希望默认路由从99.1.1.1的接口出：

cd /etc/sysconfig/network-scripts
echo 'iif eth1 table 1
from 192.168.127.8 table1' > rule-eth1
echo '192.168.127.0/24 dev eth1 table 1
default via 192.168.127.253 dev eth1 table 1' > route-eth1

重启网卡即可。