linux下ping命令出现ping: sendto: Network is unreachable

问题：ping外网出现:

　　　　 sendto: Network is unreachable

查看：

　　　　#route

　　　　Route命令 : 在数据包没有有效传递的情况下，可以利用route命令查看路由表

[root@tiny4412:/]#route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U                    eth0

　　　　发现，是由于网关，没有配置网关（gateway）

解决：

　　　

[root@tiny4412:/]#route add default gw 192.168.1.1
[root@tiny4412:/]#route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         192.168.1.1     0.0.0.0         UG                   eth0
192.168.1.0     *               255.255.255.0   U                    eth0

测试：

[root@tiny4412:/]#ping 119.75.217.56
PING 119.75.217.56 (119.75.217.56):  data bytes
 bytes from 119.75.217.56: seq= ttl= time=20.468 ms
 bytes from 119.75.217.56: seq= ttl= time=19.113 ms
 bytes from 119.75.217.56: seq= ttl= time=18.814 ms
 bytes from 119.75.217.56: seq= ttl= time=18.906 ms
 bytes from 119.75.217.56: seq= ttl= time=18.859 ms
 bytes from 119.75.217.56: seq= ttl= time=18.704 ms
 bytes from 119.75.217.56: seq= ttl= time=19.050 ms
 bytes from 119.75.217.56: seq= ttl= time=20.514 ms
 bytes from 119.75.217.56: seq= ttl= time=21.355 ms
^C
--- 119.75.217.56 ping statistics ---
 packets transmitted,  packets received, % packet loss
round-trip min/avg/max = 18.704/19.531/21.355 ms