Step-by-step – Linux Mint 20 Realtek RTL8168 Driver Installation

Installing PPA Driver

3. 3. Enabling rtl8125 PPA Repo

   Adding rtl8125 PPA for Mint GNU/Linux

   Add rtl8125 Repo for Mint

   rtl8125 PPA for Mint

4. 4. Installing Realtek rtl8168

   Now to Install Realtek rtl8168 for Mint

   This only in case your Device is still Not Working.
   Simply play:

   sudo apt install realtek-r8125-dkms

   And then Reboot with:

   sudo reboot