Using Unbound as an Ad-blocker

This page documents the steps to use Unbound as an Ad-blocker by using a publicly available blacklist in hosts file format.

Prerequisites

• You should have a dnsmasq (or another DHCP server) and unbound both working on your network.

Configuration

There are few steps to setup Unbound to Block/Refuse unwanted addresses. There are a number of freely available blacklists on the net. The installer mentioned above uses these lists by default:

• https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts
• https://sysctl.org/cameleon/hosts
• https://s3.amazonaws.com/lists.disconnect.me/simple_tracking.txt
• https://s3.amazonaws.com/lists.disconnect.me/simple_ad.txt

Alternatively, there is a set of curated lists at https://github.com/StevenBlack/hosts. There are various categories of lists there. The format of the file is a "host" (so you can put it in /etc/hosts and be done).

In this guide, we will use the hosts file format. Unbound needs to include the blacklists.conf file into its main configuration. To do so, we need to create the include file in the following format:

Contents of /etc/unbound/blacklists.conf

server: local-zone: "bad-site.com" refuse local-zone: "bad-bad-site.com" refuse local-zone: "xyz.ads-r-us.com" refuse

Here is an example shell script to download the StevenBlack hosts file, and then format it for unbound:

#!/bin/sh

echo "server:" >/etc/unbound/blacklist.conf
curl -s https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts | \
        grep ^0.0.0.0 - | \
        sed 's/ #.*$//;
        s/^0.0.0.0 \(.*\)/local-zone: "\1" refuse/' \
        >>/etc/unbound/blacklist.conf

You can run this once, or as part of a periodic cron task.

In the /etc/unbound/unbound.conf, add the following line somewhere in the config:

Contents of /etc/unbound/unbound.conf

#include "/etc/unbound/blacklist.conf"

Reload unbound, and verify the config loads.

Dnsmasq configuration

Dnsmasq defaults to using the resolver in /etc/resolv.conf — if unbound is listening on 127.0.0.1, then have it use that as the resolver.

Alternatively, if unbound is running on another interface, or on a separate machine — use the dhcp-option configuration in dnsmasq:

dhcp-option=6,[ip-of-unbound-server]

Enjoy Ad-Free browsing!

See also

unbound