Occasionally Internet disconnect on Ubuntu

Question

Edit 1: I have found the problem(hope so),and edited the question to be more precise. Sometimes the internet connection on my Ubuntu 14.04 desktop is disconnected(even when I'm using it directly or through remote connection), I have to manually click on the Internet connection icon of the taskbar, and select Wired connection 1 to make it connected again. How can I fix this problem?

Answer 1

try this in terminal,

sudo apt-get install ethtool
sudo ethtool eth0

still have the same issue,

copy the necessary files from the system and install new Ubuntu 18.04