Set Up WireGuard VPN on Debian
Updated by Linode Contributed by Linode
What is WireGuard?
WireGuard is a simple, fast, and secure VPN that utilizes state-of-the-art cryptography. With a small source code footprint, it aims to be faster and leaner than other VPN protocols such as OpenVPN and IPSec. WireGuard is still under development, but even in its unoptimized state it is faster than the popular OpenVPN protocol.
WireGuard sets up standard network interfaces (such as
wg1), which behave much like the commonly found
eth0 interface. This makes it possible to configure and manage WireGuard interfaces using standard tools such as
ip. Currently, WireGuard is only available on Linux.
Configuring WireGuard is as simple as setting up SSH. A connection is established by an exchange of public keys between server and client. Only a client that has its public key in its corresponding server configuration file is allowed to connect. A WireGuard server’s configuration file resembles the following example:
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[Interface] PrivateKey = <Private Key> Address = 192.168.2.1/24, fd86:ea04:1115::1/64 ListenPort = 51820 PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE; ip6tables -A FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -A POSTROUTING -o eth0 -j MASQUERADE PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE; ip6tables -D FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -D POSTROUTING -o eth0 -j MASQUERADE SaveConfig = true [Peer] PublicKey = <Client Public Key> AllowedIPs = 192.168.2.2/24, fd86:ea04:1115::0/64
In this guide you will learn how to:
- Configure a WireGuard server on a Linode running Debian 9.
- Configure a WireGuard client on your local computer or another Linode.
- Establish a simple peer connection between your WireGuard server and client.
CautionDo not use WireGuard for critical applications. The project is still undergoing security testing and is likely to receive frequent major updates in the future.
Before You Begin
- Deploy a Linode running Debian 9.
- Add a limited user account with
sudoprivileges to your Linode.
- Set your system’s hostname.
GRUB 2kernel is required for this guide. All distributions for all new Linodes now boot with the
GRUB 2kernel by default. However, if you are running an older distribution, you will need to check to see which kernel you are running. You can use the Update Kernel Guide to check your kernel version and change it using the Cloud Manager. Select
GRUB 2from the Boot Settings: Select a Kernel dropdown menu in Step 4 of Update Your Linode Kernel with Linode’s Cloud Manager.
Add the WireGuard repository to your sources list. Apt will automatically update the package cache.
echo "deb http://deb.debian.org/debian/ unstable main" > /etc/apt/sources.list.d/unstable-wireguard.list printf 'Package: *\nPin: release a=unstable\nPin-Priority: 150\n' > /etc/apt/preferences.d/limit-unstable
Update your packages and install WireGuard and WireGuard tools. DKMS (Dynamic Kernel Module Support) will build the WireGuard kernel module.
apt update apt install wireguard-dkms wireguard-tools
If successful, you’ll see the following output:
wireguard: Running module version sanity check. - Original module - No original module exists within this kernel - Installation - Installing to /lib/modules/4.9.0-9-amd64/updates/dkms/ depmod... DKMS: install completed. Processing triggers for libc-bin (2.24-11+deb9u4) ...
Configure WireGuard Server
Navigate to the
/etc/wireguarddirectory and generate a private and public key pair for the WireGuard server:
sudo umask 077 sudo wg genkey | tee privatekey | wg pubkey > publickey
This will save both the private and public keys; they can be viewed with
Create the file
/etc/wireguard/wg0.confand add the contents indicated below. You’ll need to enter your server’s private key in the
PrivateKeyfield, and its private IP addresses in the
Addressfield. Refer to the list below the example for more details.
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[Interface] PrivateKey = <Private Key> Address = 192.168.2.1/24, fd86:ea04:1115::1/64 ListenPort = 51820 PostUp = iptables -A FORWARD -i wg0 -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE; ip6tables -A FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -A POSTROUTING -o eth0 -j MASQUERADE PostDown = iptables -D FORWARD -i wg0 -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE; ip6tables -D FORWARD -i wg0 -j ACCEPT; ip6tables -t nat -D POSTROUTING -o eth0 -j MASQUERADE SaveConfig = true
PrivateKey the server’s private key generated in above.
Address defines the private IPv4 and IPv6 addresses for the WireGuard server. Each peer in the VPN network should have a unique value for this field. Typical values are
192.168.2.1/24. This is not the same as a private IP address that Linode can assign to your Linode instance.
ListenPort specifies which port WireGuard will use for incoming connections. The default is
51820. What you set here you will need to reference in your firewall settings later.
PostUp and PostDown defines steps to be run after the interface is turned on or off, respectively. In this case,
iptablesis used to set Linux IP masquerade rules to allow all the clients to share the server’s IPv4 and IPv6 address. The rules will then be cleared once the tunnel is down.
SaveConfig tells the configuration file to automatically update whenever a new peer is added while the service is running.
Set Up Firewall Rules
sudo apt-get install ufw
Allow SSH connections and WireGuard’s VPN port:
sudo ufw allow 22/tcp sudo ufw allow 51820/udp sudo ufw enable
Verify the settings:
sudo ufw status verbose
Start the WireGuard Service
sudo wg-quick up wg0
wg-quickis a convenient wrapper for many of the common functions in
wg. You can turn off the wg0 interface with
wg-quick down wg0
Enable the WireGuard service to automatically restart on boot:
sudo systemctl enable [email protected]
Check if the VPN tunnel is running with the following two commands:
sudo wg show
You should see a similar output:
[email protected]:/# wg show interface: wg0 public key: Nrl2nVQxSwrKrvz6jQcrsziuVRPWT9N1Q8/yaQkAXUg= private key: (hidden) listening port: 51820
You may need to install net-tools to run
sudo apt-get install net-toolsif needed.
sudo ifconfig wg0
Your output should resemble the following:
[email protected]:/# ifconfig wg0 wg0: flags=209
mtu 1420 inet 192.168.2.1 netmask 255.255.255.0 destination 192.168.2.1 inet6 fd86:ea04:1115::1 prefixlen 64 scopeid 0x0 unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 1 (UNSPEC) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Configure WireGuard Client
The process for setting up a client is similar to setting up the WireGuard server. When using Debian as your client’s operating system, the only difference between the client and the server is the configuration file. In this section, you will configure a WireGuard client on Debian 9.
NoteFor installation instructions on other operating systems, see the WireGuard docs.
Follow the steps in the Install WireGuard section of the guide.
Once you have installed WireGuard, follow the steps in the Configure WireGuard Server section. Replace the example configuration file with the example file below.
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[Interface] PrivateKey = <Client Private Key> Address = 192.168.2.2/24, fd86:ea04:1115::5/64
The difference between the client and the server’s configuration file,
wg0.conf, is it contains its own IP addresses and does not contain the
Set up Firewall rules on your WireGuard client.
Connect the Client and Server
Stop the interface with
sudo wg-quick down wg0on both the client and the server.
wg0.conffile on the client to add the server’s public key, public IP address, port, and allowed IPs.
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[Peer] PublicKey = <Server Public key> Endpoint = <Server Public IP>:51820 AllowedIPs = 192.168.2.2/24, fd86:ea04:1115::0/64
wg0.conffile on the server to add the client’s public key and allowed IPs.
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[Peer] PublicKey = <Client Public Key> AllowedIPs = 192.168.2.2/24, fd86:ea04:1115::0/64
wgservice on both the server and the client:
sudo wg-quick up wg0
You can also add peers to the server from the command line. This information will be added to the config file automatically because of the
SaveConfigoption specified in the
Run the following command from the server. Replace the example IP addresses with those of the client:
sudo wg set wg0 peer <Client Public Key> allowed-ips 220.127.116.11/24,fd86:ea04:1115::5/64
Verify the connection. The following command can be run from both the client or the server:
Regardless of which method you choose to add peer information to WireGuard, the Peer section appears in the output of the
sudo wgcommand if the setup was successful.
[email protected]:/# sudo wg interface: wg0 public key: Nrl2nVQxSwrKrvz6jQcrsziuVRPWT9N1Q8/yaQkAXUg= private key: (hidden) listening port: 51820 peer: I8s7YGMuUbPvStb686JjxfUAa/tzqZhcLDgiqRKlbWs= endpoint: 18.104.22.168:59850 allowed ips: 192.168.2.0/24, fd86:ea04:1115::/64
This Peer section will be automatically added to
wg0.confwhen the service is restarted. If you would like to add this information immediately to the config file, you can run:
sudo wg-quick save wg0
Additional clients can be added using the same procedure.
Test the Connection
Return to the client and ping the server:
Once you’ve successfully established the ability to ping the server from the client, run the following command:
The last two lines of the output from running the
wgcommand should be similar to:
latest handshake: 1 minute, 17 seconds ago transfer: 98.86 KiB received, 43.08 KiB sent
This indicates that you now have a private connection between the server and client. If you did not successfully ping the server from the client you will not see these lines. You can also ping the client from the server to verify that the connection works both ways.
The process used in this guide can be extended to configure network topologies. As mentioned previously, WireGuard is an evolving technology. If you use WireGuard, you should monitor the official documentation and todo list for critical updates and new/upcoming features.
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This guide is published under a CC BY-ND 4.0 license.