Instal Debian 9 w/o Network Missing Realtek 8812AU Driver

Question

I am trying to install Debian 9.80, but when I am asked for which package manager I would like to use, I choose default options, but I can't go on without an internet connection. I skipped past it, but I can't find a way to install packages without going through a million dependencies using the https://www.debian.org/distrib/packages. My adapter is a BrosTrend AC1200 AC3 Wifi Adapter. I gotten it to work on Ubuntu using https://blog.danielscrivano.com/installing-rtl8812au-on-linux-for-wireless-dual-band-usb-adapters/ but I want to get it working on Debian.

Answer 1

Because the installation is done without an Internet connection apt will not be configured correctly.

1) Edit your sources.list:

sudo nano /etc/apt/sources.list

with the following lines:

deb http://deb.debian.org/debian stretch main
deb-src http://deb.debian.org/debian stretch main

deb http://deb.debian.org/debian-security/ stretch/updates main
deb-src http://deb.debian.org/debian-security/ stretch/updates main

deb http://deb.debian.org/debian stretch-updates main
deb-src http://deb.debian.org/debian stretch-updates main

Then:

sudo apt update 
sudo apt upgrade
sudo reboot

2) Installing the Realtek driver following the steps described on the blog posted in your question ( linux-headers-generic isn't available for debian it will be replaced by linux-headers-$(uname -r))

  sudo apt-get install linux-headers-$(uname -r) build-essential git
  git clone https://github.com/scrivy/rtl8812AU_8821AU_linux.git
  cd rtl8812AU_8821AU_linux
  make
  sudo make install
  sudo modprobe rtl8812au