diff --git a/doc/gitian-building/gitian-building-setup-gitian-debian.md b/doc/gitian-building/gitian-building-setup-gitian-debian.md
index 2f8713c11..f5e112cd9 100644
--- a/doc/gitian-building/gitian-building-setup-gitian-debian.md
+++ b/doc/gitian-building/gitian-building-setup-gitian-debian.md
@@ -1,110 +1,122 @@
 Table of Contents
 -----------------
 
 - [Setting up Debian for Gitian building](#setting-up-debian-for-gitian-building)
 - [Installing Gitian](#installing-gitian)
 - [Setting up the Gitian image](#setting-up-the-gitian-image)
 
 
 Setting up Debian for Gitian building
 -------------------------------------
 
 In this section we will be setting up the Debian installation for Gitian building.
 We assume that a user `gitianuser` was previously added.
 
 First we need to set up dependencies. Type/paste the following in the terminal:
 
 ```bash
-sudo apt-get install git ruby apt-cacher-ng qemu-utils debootstrap lxc python-cheetah parted kpartx bridge-utils make ubuntu-archive-keyring curl firewalld apparmor
+sudo apt-get install git ruby apt-cacher-ng qemu-utils debootstrap lxc python-cheetah parted kpartx bridge-utils make ubuntu-archive-keyring curl firewalld apparmor iptables
+```
+
+Find the device name of your network card. You can list your connections with
+```bash
+ip address
+```
+Examples: `eth0`, `eno1`, ...
+Save it to the NET_DEV variable:
+```bash
+sudo -s
+NET_DEV=<your device name>
 ```
 
 Then set up LXC and the rest with the following, which is a complex jumble of settings and workarounds:
 
 ```bash
-sudo -s
 # the version of lxc-start in Debian needs to run as root, so make sure
 # that the build script can execute it without providing a password
 echo "%sudo ALL=NOPASSWD: /usr/bin/lxc-start" > /etc/sudoers.d/gitian-lxc
 echo "%sudo ALL=NOPASSWD: /usr/bin/lxc-execute" >> /etc/sudoers.d/gitian-lxc
 # make /etc/rc.local script that sets up bridge between guest and host
 echo '#!/bin/sh -e' > /etc/rc.local
 echo 'brctl addbr br0' >> /etc/rc.local
 echo 'ip addr add 10.0.3.1/24 broadcast 10.0.3.255 dev br0' >> /etc/rc.local
 echo 'ip link set br0 up' >> /etc/rc.local
 echo 'firewall-cmd --zone=trusted --add-interface=br0' >> /etc/rc.local
+echo "iptables -t nat -A POSTROUTING -o ${NET_DEV} -j MASQUERADE" >> /etc/rc.local
+echo 'echo 1 > /proc/sys/net/ipv4/ip_forward' >> /etc/rc.local
 echo 'exit 0' >> /etc/rc.local
 chmod +x /etc/rc.local
 # make sure that USE_LXC is always set when logging in as gitianuser,
 # and configure LXC IP addresses
 echo 'export USE_LXC=1' >> /home/gitianuser/.profile
 echo 'export GITIAN_HOST_IP=10.0.3.1' >> /home/gitianuser/.profile
 echo 'export LXC_GUEST_IP=10.0.3.5' >> /home/gitianuser/.profile
 reboot
 ```
 
 At the end Debian is rebooted to make sure that the changes take effect. The steps in this
 section only need to be performed once.
 
 **Note**: When sudo asks for a password, enter the password for the user `gitianuser` not for `root`.
 
 Installing Gitian
 -----------------
 
 Re-login as the user `gitianuser` that was created during installation.
 The rest of the steps in this guide will be performed as that user.
 
 There is no `python-vm-builder` package in Debian, so we need to install it from source ourselves,
 
 ```bash
 wget http://archive.ubuntu.com/ubuntu/pool/universe/v/vm-builder/vm-builder_0.12.4+bzr494.orig.tar.gz
 echo "76cbf8c52c391160b2641e7120dbade5afded713afaa6032f733a261f13e6a8e  vm-builder_0.12.4+bzr494.orig.tar.gz" | sha256sum -c
 # (verification -- must return OK)
 tar -zxvf vm-builder_0.12.4+bzr494.orig.tar.gz
 cd vm-builder-0.12.4+bzr494
 sudo python setup.py install
 cd ..
 ```
 
 **Note**: When sudo asks for a password, enter the password for the user `gitianuser` not for `root`.
 
 Clone the git repositories for bitcoin and Gitian.
 
 ```bash
 git clone https://github.com/devrandom/gitian-builder.git
 git clone https://github.com/Bitcoin-ABC/bitcoin-abc.git
 ```
 
 Setting up the Gitian image
 ---------------------------
 
 Gitian needs a virtual image of the operating system to build in.
 Currently this is Ubuntu Bionic x86_64, however previous releases were built
 with Ubuntu Trusty x86_64.
 This image will be copied and used every time that a build is started to
 make sure that the build is deterministic.
 Creating the image will take a while, but only has to be done once.
 
 Execute the following as user `gitianuser`:
 
 ```bash
 cd gitian-builder
 bin/make-base-vm --lxc --arch amd64 --distro debian --suite stretch
 ```
 
 There will be a lot of warnings printed during the build of the image. These can be ignored.
 
 **Note**: When sudo asks for a password, enter the password for the user `gitianuser` not for `root`.
 
 Downloading dependencies
 ------------------------
 
 Gitian may have problems connecting to the internet, which can make the build
 flacky. In order to avoid this, it is possible to download dependencies ahead
 of time.
 
 Execute the following as user `gitianuser`:
 
 ```bash
 cd gitian-builder
 make -C ../bitcoin-abc/depends download SOURCES_PATH=`pwd`/cache/common
 ```