Ubuntu22.0 suddenly failed to connect to the Internet after booting up.The network icon in the upper right corner disappeared, and there was no "wired" network option in the settings. Only VPN was left. I tried many times. method, and finally solved it.
I saw some solutions by directly using the following two commands, but I can't do this.
sudo dhclient ens33
sudo ifconfig ens33
I saw the same problem later and used the following two commands to solve it. There is also a network icon in the upper right corner, and "Wired" is also available in the settings.
参考：https://blog.csdn.net/m0_52709408/article/details/127527890
sudo nmcli networking off
sudo nmcli networking on