从 17.10 升级到 18.04 后，以太网连接未显示在网络中。
我试过这个。
$ ifconfig
enp2s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 28:f1:0e:33:c6:8c txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 92859 bytes 31342466 (31.3 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 92859 bytes 31342466 (31.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp1s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.70 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::f604:8dc4:abd3:f1a9 prefixlen 64 scopeid 0x20<link>
ether e4:02:9b:10:39:f2 txqueuelen 1000 (Ethernet)
RX packets 419663 bytes 534953715 (534.9 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 324770 bytes 41353378 (41.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
这意味着笔记本电脑正在断开以太网电缆，但未显示在网络中。Wifi 工作正常。我已经尝试了多种解决方案，但对我而言不起作用。请帮忙！