ubuntu连有线网 无法连接外网

问题：连上网线后，有ip，但是无法访问外网。

我的解决方案是：

.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-:~$ ifconfig
enp3s0    Link encap:Ethernet  HWaddr :::a5::3d
          inet addr:10.58.101.247  Bcast:10.58.103.255  Mask:255.255.252.0
          inet6 addr: fe80::::3f1e:fe3/ Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:  Metric:
          RX packets: errors: dropped: overruns: frame:
          TX packets: errors: dropped: overruns: carrier:
          collisions: txqueuelen:
          RX bytes: (3.7 MB)  TX bytes: (238.7 KB)  

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::/ Scope:Host
          UP LOOPBACK RUNNING  MTU:  Metric:
          RX packets: errors: dropped: overruns: frame:
          TX packets: errors: dropped: overruns: carrier:
          collisions: txqueuelen:
          RX bytes: (72.3 KB)  TX bytes: (72.3 KB)  

wlp4s0    Link encap:Ethernet  HWaddr a4::b9:0a::b1
          UP BROADCAST MULTICAST  MTU:  Metric:
          RX packets: errors: dropped: overruns: frame:
          TX packets: errors: dropped: overruns: carrier:
          collisions: txqueuelen:
          RX bytes: (0.0 B)  TX bytes: (0.0 B)
.命令行添加或修改网络参数
zhuml@zhuml-Latitude-:~$ sudo gedit /etc/network/interfaces
弹出一个文本窗，如下：
# interfaces() file used by ifup() and ifdown()
auto lo
iface lo inet loopback
在里面添加以太网的相关信息
# interfaces() file used by ifup() and ifdown()
auto lo
iface lo inet loopback  

auto esp3s0
iface esp3s0 inet dhcp  

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