Configure Ubuntu Pi-hole for Cloudflare DNS over HTTPS

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Pi-hole DNS over HTTPS

I installed OpenVPN VPN solutions on Ubuntu for my businesses to secure all data communications. I also set up Pin-hole ad blocker on Ubuntu server along with OpenVPN. How do I force Pi-hole to use Cloudflare DNS over HTTPS (DoH) to increase my privacy and security by preventing eavesdropping and manipulation of DNS data by man-in-the-middle attacks?Pi-hole is a free and open source software to block Internet ads and tracking domains. The most significant advantage is ad blocking on all devices on the network from your smartphone to your tablets including all desktop computers and apps. This page shows how to configure Cloudflare DNS over HTTPS service along with Pi-Hole server running on Ubuntu Linux 18.04 LTS.

DNS over HTTPS (DoH) is a protocol for DNS resolution through the HTTPS protocol. DoH increase your user’s privacy and security and help prevent manipulation of DNS.

How to configure Pi-hole for Cloudflare DNS

Naturally, you must set up and configure OpenVPN Server on Ubuntu and Pi-hole on Ubuntu Linux 18.04 LTS.

Download Cloudflared

There are numerous DNS over HTTPS (DoH) clients you can use to connect to Cloudflare DNS server IP address 1.1.1.1 and 1.0.0.1. We are going to use Cloudflared by downloading .deb package for Ubuntu. Type the following wget command:

cd /tmp

wget https://bin.equinox.io/c/VdrWdbjqyF/cloudflared-stable-linux-amd64.deb



Install Cloudflared

Installing cloudflared is comfortable job with the help of apt command or apt-get command:

$ sudo apt install ./cloudflared-stable-linux-amd64.deb

Verify installation, run:

cloudflared --version



How to add a new Ubuntu Linux user for cloudflared

In order to configuring cloudflared to run on startup, first add a new Linux user named cloudflared using the useradd command:

sudo useradd -r -M -s /usr/sbin/nologin -c "Cloudflared user" cloudflared

Verify that user has been created with the help of grep command and /etc/passwd :

grep '^cloudflared' /etc/passwd

Alternatively, one can use the id command as well on Ubuntu to verify cloudflared user account:

id cloudflared

Lock down the Linux account named cloudflared:

sudo passwd -l cloudflared

sudo chage -E 0 cloudflared

You can see account aging information, run chage command:

sudo chage -l cloudflared



How to configuring cloudflared dns

Create a file named /etc/default/cloudflared as follows using text editor such as vim command or nano command:

sudo vi /etc/default/cloudflared

Append the following text:

## args for cloudflared ## ## 5353 is localhost: 5353 . This is where dns queries are sent by pi-hole ## ## 1.1.1.1 and 1.0.0.1 are Cloudflare DNS servers ## CLOUDFLARED_OPTS = --port 5353 --upstream https://1.1.1.1/dns-query --upstream https://1.0.0.1/dns-query ## args for cloudflared ## ## 5353 is localhost:5353. This is where dns queries are sent by pi-hole ## ## 1.1.1.1 and 1.0.0.1 are Cloudflare DNS servers ## CLOUDFLARED_OPTS=--port 5353 --upstream https://1.1.1.1/dns-query --upstream https://1.0.0.1/dns-query

Save and close the file in vim.

Set up permission using chown command:

sudo chown -v cloudflared:cloudflared /usr/local/bin/cloudflared /etc/default/cloudflared

Sample outputs:

changed ownership of '/usr/local/bin/cloudflared' from root:root to cloudflared:cloudflared changed ownership of '/etc/default/cloudflared' from root:root to cloudflared:cloudflared

How to create systemd startup script for Cloudflared

Type the following command:

sudo vi /lib/systemd/system/cloudflared.service

Append the following config:

[ Unit ] Description = cloudflared DoH proxy After = syslog.target network-online.target [ Service ] Type = simple User = cloudflared EnvironmentFile = /etc/default/cloudflared ExecStart = /usr/local/bin/cloudflared proxy-dns $CLOUDFLARED_OPTS Restart = on-failure RestartSec = 10 KillMode = process [ Install ] WantedBy = multi-user.target [Unit] Description=cloudflared DoH proxy After=syslog.target network-online.target [Service] Type=simple User=cloudflared EnvironmentFile=/etc/default/cloudflared ExecStart=/usr/local/bin/cloudflared proxy-dns $CLOUDFLARED_OPTS Restart=on-failure RestartSec=10 KillMode=process [Install] WantedBy=multi-user.target

Enable and start the cloudflared service

Run the following systemctl command:

sudo systemctl enable cloudflared

sudo systemctl start cloudflared

echo $?

sudo systemctl status cloudflared



Save and exit from the vim.

Verify that cloudflared working

Run the dig command or host command as follows to test Cloduflare DoH proxy:

dig -p 5353 www.nixcraft.com @127.0.0.1



Another option is to check and find out if the TCP/UDP port 5353 working using the nmap command:

sudo nmap -Pn -sT -sU -p 5353 127.0.0.1

Sample outputs:

Starting Nmap 7.60 ( https://nmap.org ) at 2020 -04-08 13 : 55 UTC Nmap scan report for localhost ( 127.0.0.1 ) Host is up ( 0.00013s latency ) . PORT STATE SERVICE 5353 /tcp open rlm 5353 /udp open|filtered unknown Nmap done: 1 IP address ( 1 host up ) scanned in 2.05 seconds Starting Nmap 7.60 ( https://nmap.org ) at 2020-04-08 13:55 UTC Nmap scan report for localhost (127.0.0.1) Host is up (0.00013s latency). PORT STATE SERVICE 5353/tcp open rlm 5353/udp open|filtered unknown Nmap done: 1 IP address (1 host up) scanned in 2.05 seconds

Configure Ubuntu Pi-hole for Cloudflare DNS over HTTPS

Now, everything is set up and running. Hence, it is time to configure Pi-hole to use the local cloudflared service running on 127.0.0.1 port 5353. Fire the web browser and type the pi-hole admin url as per your setup. In my case my OpenVPN and pi-hole running on 10.8.0.1, hence I type:

http://10.8.0.1/



How do I upgrade cloudflard?

Click on the> Chooseunder Upstream DNS Servers and enter “” > Scroll down and click on thebutton.

Download the latest version from the url and install it as follows:

$ cloudflared --version

cloudflared version 2020.8.2 (built 2020-08-20-1712 UTC)

$ cd /tmp

$ wget https://bin.equinox.io/c/VdrWdbjqyF/cloudflared-stable-linux-amd64.deb

$ sudo apt install ./cloudflared-stable-linux-amd64.deb

$ sudo systemctl restart cloudflared

$ cloudflared --version

cloudflared version 2020.8.2 (built 2020-08-20-1712 UTC)

Conclusion

This page explained DoH, and you learned how to implement DNS-Over-HTTPS on PiHole. For more information see this page here and here.

