Install Realtek 2.5G GBE (RTL8156) driver on Ubuntu 20.04

Refer to: https://zhuanlan.zhihu.com/p/347271959

1. Download RTL8156 Linux driver from:

https://www.realtek.com/en/component/zoo/category/network-interface-controllers-10-100-1000m-gigabit-ethernet-usb-3-0-software

2. Install DKMS

> sudo apt install dkms

3. Extract source code:

> sudo tar -xvf r8152.53.56-2.14.0.tar -C /usr/src/

4. Create dkms.conf

> sudo nano /usr/src/r8152-2.14.0/dkms.conf

======================================

PACKAGE_NAME="r8152"

PACKAGE_VERSION="2.14.0"

BUILT_MODULE_NAME[0]="$PACKAGE_NAME"

DEST_MODULE_LOCATION[0]="/updates/dkms"

AUTOINSTALL="YES"

REMAKE_INITRD="YES"

CLEAN="rm src/@PKGNAME@.ko src/*.o || true"

======================================

5. Install driver:

> sudo dkms add -m r8152 -v 2.14.0

> sudo dkms build -m r8152 -v 2.14.0

> sudo dkms install -m r8152 -v 2.14.0

> sudo depmod -a

> sudo modprobe r8152