sudo service network-manager stop
sudo rm /var/lib/NetworkManager/NetworkManager.state
sudo service network-manager start
erskine@erskine-virtual-machine:~$ sudo ifconfig ens33 up
erskine@erskine-virtual-machine:~$ ifconfig
erskine@erskine-virtual-machine:~$ sudo dhclient -i ens33
按照每行一行行输入就行