MSI Z490-A Pro, Ubuntu 20.04 did not recognize the wired LAN, so Driver introduction memo at that time.
Download files for RTL8125 driver https://www.realtek.com/en/component/zoo/category/network-interface-controllers-10-100-1000m-gigabit-ethernet-pci-express-software Download Unix (Linux) 2.5G Ethernet LINUX driver r8125 for kernel up to 5.6
Creation of RTL8125.ko
Unzip the file downloaded in $ sudo bash ./autorun.sh Then, it will be created in the directory of 3.
https://qiita.com/bunnyhopper_isolated/items/40aea93b72fb11a0d6a0