WireGuard on a router

WIREGUARD

Last updated: 12 October 2022


In this guide, we walk you through the steps to set up and run WireGuard® on a router.

If you run into any issues while testing WireGuard, please contact support@mullvad.net and let us know what you experience.

Installing OpenWrt on your router (Version 21.02.3 has been used here)

First, check OpenWrt's list of supported routers to make sure yours is included.

Installing WireGuard and Mullvad on your router comes with some benefits:

  • You can secure your whole network and all devices connected to the router.
  • You can run Mullvad on more than five devices (all devices connected to the router).
  • Via the router, you can even run Mullvad on devices that have no support for WireGuard.
  • A router is designed for routing, naturally, and is not disturbed by other programs and settings like a program in a computer might be. It works well and is stable.

Installing WireGuard

What you need in order to proceed:

  • a router with a fresh installation of OpenWrt.
  • a public/private key pair to use with WireGuard (will be described below).
  • an IP address to use (will be described below).

Update the router's firmware to OpenWRT

Follow your router's instructions on how to connect and update the firmware to the OpenWrt firmware that you previously downloaded.

The router normally displays some status information and then restarts. Take extra care in downloading the correct version since doing this incorrectly could "brick" your router, making it completely unusable.

Initial configuration of OpenWrt

  1. Open a browser and navigate to http://192.168.1.1/.
  2. Click the Login button. This logs you in with the default root user and no password.
  3. Once the Status page loads, you will see a message at the top saying “No password set!” Click on System - Administration
  4. On the Router Password page, set a secure and memorable password. Click the Save button.
  5. On the same page, in the SSH Access section, set the interface to LAN. Click the Save & Apply button.

Install WireGuard

1. From the System drop-down menu, click on Software , Click "Update lists...", then when finished updating click "Dismiss"

2. In the Download and install package field enter: luci-proto-wireguard and click OK, click Install. Then Dismiss the windows when installed. Repeat and make sure wireguard-tools is installed also.

3. Click System - Reboot (Make sure to reboot the router otherwise other steps will most likely fail)

 

Public/private key pair

If you do not have a public/private key pair to use with WireGuard, then you can use SSH to connect to the router as described earlier, and run:

wg genkey | tee privatekey | wg pubkey > publickey

Your public key will be in the file "publickey" and your private key in the file "privatekey".

Display the contents of publickey by issuing: cat publickey which is later used for pushing it to the api.
Display the contents of privatekey issuing: cat privatekey which is later used when configuring the WGInterface.

If you're running WireGuard on multiple devices, generate a separate key pair for each device. Also make sure to connect the router to a unique server that you do not use on other devices that will be using the router's VPN. You will otherwise run into connectivity issues.

Getting an IP to use with Mullvad

While connected to the router using ssh:

First install curl: opkg update && opkg install curl

curl https://api.mullvad.net/wg/ -d account=YOURMULLVADACCOUNTNUMBER --data-urlencode pubkey=YOURPUBLICKEY

The IP:address to use with Mullvad will be returned.

Add the WireGuard interface

In the main menu, select Network- Interfaces and then click on "Add new interface". Name the interface  WGINTERFACE and select Protocol WireGuard VPN and press Create interface in order to start configure the new interface.

Configure WGInterface settings

Make the following changes:

  • Private Key –  use the one you previously generated.
  • IP Addresses – replace 10.99.0.5 with the IP address you received from Mullvadscreenshot of LEDE interfaces page

Click image to enlarge.

Click Peers, then Add Peer

  • Public Key – use the key that corresponds with the Mullvad WireGuard server of your choosing from Servers
  • Route Allowed IPs - Make sure this is checked
  • Endpoint Host (Peers)– use the IP address that corresponds with the Mullvad WireGuard server of your choosing.
  • Endpoint Port - change to 51820
  • Allowed IPs - change to 0.0.0.0/0

interfaces-peers


Click image to enlarge.

Click on the Advanced Settings tab and check the box next to "Force link". Leave the other options on this page as is (Setting does not exist on some versions)

Save and apply settings!

Add new firewall zone

From the Network drop-down menu, click on Firewall.

Under Zones. Create a new zone and set it up as shown below. We named ours "WGZONE".

Input: reject
Output: accept
Forward: reject
Masquerading: checked
MSS clamping: checked
Covered networks: WGINTERFACE
 
Click Save


Click on Edit the lan zone and set "Allow forward to destination zones" to WGZONE:WGINTERFACE" as the only option under allowed destinations.

 


Click image to enlarge.

DHCP and DNS settings

Under Network go to the DHCP and DNS settings.

Next to DNS forwarding, add 10.64.0.1

screenshot of LEDE DHCP and DNS settings page
Click image to enlarge.

Change DNS on LAN Interface

Navigate to Network → Interfaces → LAN (click edit) and make the following changes:

  • IPv4 address – change this to "192.168.99.1" (this ensures that it won't conflict with our other routers commonly running on 192.168.0.1 or 192.168.1.1) . Keep in mind after this you will access the OpenWRT device on 192.168.99.1

Click on DHCP server - Advanced Settings - DHCP-Options: 6,10.64.0.1

(If you'd like to learn more about DNS leaks, check out our guide on DNS leaks.)

Change DNS on WAN Interface

Network > Interfaces > WAN (click edit) > Advanced Settings > Use DNS servers advertised by peer (disable)

Use custom DNS servers: 193.138.218.74

Restart the router

In order to make everything start properly, restart the router. Some settings require you to restart the WGInterface in order for the changes to be applied. Sometimes you need to restart the router more than once!

Test your IP address

Use our Connection check to see which IP address you are using. It should be one of Mullvad's and not your own.

Add a watchdog

Adding a watchdog will ensure that the router restarts if anything stops working.

Important: Complete this step only after you have confirmed that the router is working properly.

Use SSH to log in to the router and add the file wg-watchdog.sh (provided below) in /root using nano.

First install nano: opkg update && opkg install nano

Then run the command nano /root/wg-watchdog.sh.

The wg-watchdog.sh file:

#!/bin/sh
# ping mullvad dns that can only be reached via the VPN tunnel
# if no contact, reboot!

tries=0
while [[ $tries -lt 5 ]]
do
        if /bin/ping -c 1 10.64.0.1
        then
                echo "wg works"
                exit 0
        fi
        echo "wg fail"
        tries=$((tries+1))
done
echo "wg failed 5 times - rebooting"
reboot

Make the file executable using the command chmod +x /root/wg-watchdog.sh.

Afterward, add the following entry in System → Scheduled Tasks in LuCI:

*/10 * * * * /root/wg-watchdog.sh

Multihop using SOCKS5

With WireGuard you can make use of multihop, which routes your Internet traffic through an entry server to an exit server, instead of using only an exit server.

All of our WireGuard servers are connected to all other WireGuard servers via WireGuard tunnels. In addition, each of the servers have a SOCKS5 proxy installed which makes it possible to enter a SOCKS5 proxy in a web browser (or other program) and get multihop.

See our WireGuard SOCKS5 guide to learn how to use a SOCKS5 proxy in a web browser. You can find the SOCKS5 proxy addresses in our Servers list, for example us10-wg.socks5.relays.mullvad.net.

To allow resolving the internal IP address of the SOCKS5 proxy you may have to disable "DNS rebind protection" in OpenWrt under Network > DHCP and DNS.

Troubleshooting

DNS leaks

If the router is leaking the DNS servers from your Internet provider then try to change some of the following settings and then restart the router and the computers/devices in the local network that are connected to the router.

  1. Network > Interfaces > WAN (click edit) > Advanced Settings > Use DNS servers advertised by peer (disable)
  2. Network > DHCP and DNS > Advanced Settings > Strict order (enable)
  3. Network > Interfaces > LAN > DHCP Server > Advanced Settings > "Force DHCP on this network even if another server is detected" (enable)
  4. Network > Interfaces > LAN > DHCP Server > IPv6 Settings > Router Advertisement-Service (disable)

Firmware version

To find out which version of WireGuard you have running, SSH to the router and issue the command dmesg | grep -i wireguard.io.

The router will respond with the version of WireGuard, for example "[   10.339423] wireguard: WireGuard 0.0.20170517 loaded. See www.wireguard.io for information."

General problems

Restart the router. Some settings, like the watchdog and adding the WireGuard interface, need a restart in order for changes to be applied.

Important: Your router needs to have the proper time and date, otherwise you'll likely run into connectivity issues.

"WireGuard" is a registered trademark of Jason A. Donenfeld.