ubuntu连有线网 无法连接外网

1.通过命令行ifconfig命令查看以太网（即网线插口）的名称，如下图，‘enp3s0‘是网线插口（Ethernet以太网）：

zhuml@zhuml-Latitude-3350:~$ ifconfig  
enp3s0    Link encap:Ethernet  HWaddr 14:18:77:a5:24:3d    
          inet addr:10.58.101.247  Bcast:10.58.103.255  Mask:255.255.252.0  
          inet6 addr: fe80::2883:9232:3f1e:fe3/64 Scope:Link  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1  
          RX packets:13212 errors:0 dropped:0 overruns:0 frame:0  
          TX packets:1696 errors:0 dropped:0 overruns:0 carrier:0  
          collisions:0 txqueuelen:1000   
          RX bytes:3760852 (3.7 MB)  TX bytes:238743 (238.7 KB)  
  
lo        Link encap:Local Loopback    
          inet addr:127.0.0.1  Mask:255.0.0.0  
          inet6 addr: ::1/128 Scope:Host  
          UP LOOPBACK RUNNING  MTU:65536  Metric:1  
          RX packets:558 errors:0 dropped:0 overruns:0 frame:0  
          TX packets:558 errors:0 dropped:0 overruns:0 carrier:0  
          collisions:0 txqueuelen:1000   
          RX bytes:72352 (72.3 KB)  TX bytes:72352 (72.3 KB)  
  
wlp4s0    Link encap:Ethernet  HWaddr a4:02:b9:0a:76:b1    
          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)  
2.命令行添加或修改网络参数
zhuml@zhuml-Latitude-3350:~$ sudo gedit /etc/network/interfaces  
弹出一个文本窗，如下：
# interfaces(5) file used by ifup(8) and ifdown(8)  
auto lo  
iface lo inet loopback  
在里面添加以太网的相关信息
# interfaces(5) file used by ifup(8) and ifdown(8)  
auto lo  
iface lo inet loopback  
  
auto esp3s0  
iface esp3s0 inet dhcp  

3.重启网络
zhuml@zhuml-Latitude-3350:~$ sudo /etc/init.d/networking restart  
现在应该能够恢复插上网线，能够上网；