DD-WRT routers and Mullvad VPN - Guides

What is DD-WRT?

As stated on dd-wrt.com, DD-WRT is a Linux based alternative OpenSource firmware.

This guide uses OpenVPN protocol to connect to the Mullvad VPN servers.

Using Mullvad on your router gives you the following 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 OpenVPN.
A router is designed for routing, naturally, and is not disturbed by other apps and settings like a computer might be.

Installing DD-WRT on your router

Search in the router database on the dd-wrt website to find out if your router is supported. If so read the installation information in the Firmware FAQ.

Expected performance of OpenVPN on a router

Running OpenVPN on a router is demanding due to the encryption, and OpenVPN can only use one CPU core since it's single threaded. On a router with a 400mhz ARM CPU, you can expect performance around 7–10Mbps. It scales relatively linearly, so on a router with 1.6Ghz ARM CPU we would expect performance around 30–40Mbps. Generally x86 CPUs will perform a lot better.

For other speed related questions, please read our speed guide.

Connecting to the router

A DD-WRT router's default IP address is normally 192.168.1.1. Sometimes this address is in conflict with other routers and you might have to change it. If so, try 192.168.10.1, but remember to change the default address everywhere that it is mentioned in this guide.

The first time you connect, you will be prompted to replace the admin login username and password with your own.

Setting up OpenVPN

Follow the instructions below (please read through once before starting).
This guide was written and tested on DD-WRT v3.0 [Beta] build 51440.

VPN tab

Click on the tab Services and then the subtab VPN. This is where you will set up the Mullvad VPN.

OpenVPN Client: Enable

Next to Enable Client, select Enable.

Server IP / Name : Port

To find the server IP use our Servers list. Make sure to select only OpenVPN in the server type filter in the top. Select the country and city that you want and then click on one of the servers to find the IPv4 address to it.

In this example we'll use 185.213.154.140 (which is the IP address for se-got-010.relays.mullvad.net).

After the server IP you can set the port. Set it to for example 1300. If you need to use TCP then set the port to 443 (and set Tunnel Protocol to TCP4).

Tunnel Protocol

Set this to UDP4 unless you need to connect with TCP4 on port 443.

Encryption Cipher

Change to "AES-256-GCM".

Hash Algorithm

Change to "SHA1".

User Pass Authentication

Change to Enable. Enter your Mullvad account number (without any spaces) as username, and use the password "m".

Advanced Options

Next to Advanced Options, check "Enable".

Compression

Make sure this is set to "Disabled" and not "No" .

NAT

Change to "Enable"

Killswitch

Check the box.

Verify Server Certificate

Check the box.

Click on the picture to open it in a new tab.

CA Certificate

Copy and paste the following text in the text area:

Apply Settings

Click on the green Apply Settings button.

Enable IPv6

Click on the Setup tab and then the sub tab IPv6.
Next to Enable IPv6, select Enable. Mullvad will not function without this.
Click on the Type drop-down menu and select DHCPv6 with Prefix Delegation.
No other setting needs to be changed.
Click on Apply Settings.

Check the connection status

Click on the Status tab and then the subtab OpenVPN.

In the top it should say:

State
Client: CONNECTED SUCCESS

Click on the Refresh button to update the status.

Set the DNS

Now you will set the DNS to Mullvad's DNS. This will ensure that information is not leaked to the provider running the local network and will therefore keep them from seeing which domain names are looked up.

Basic Setup tab

While still on the Setup tab, click on the Basic Setup tab

Static DNS

Set the following DNS servers:
Static DNS 1: 10.8.0.1

Note that the DNS server 193.138.218.74 is decommissioned and no longer works

Next to Local DNS , change the four fields so that the string reads 1.1.1.1 (or any other DNS server you might wish to use)

Apply

Click on the Apply Settings button.

Secure your WiFi

Wireless Security tab

Click on the tab Wireless and then the subtab Wireless Security.

Encryption and password

By default, the WiFi is unprotected on DD-WRT. You need to set Security Mode to WPA. Set the algorithm to CCMP-238 (AES) and enter a strong password in the WPA Shared Key field.
Some routers have several WiFi networks; make sure you secure all of them.

Click on the Apply Settings button.

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.

How to add a port to be forwarded to any client behind the router (optional)

Replace 12345 with the port number you have been assigned.

iptables -t nat -I PREROUTING -i tun+ -p tcp --dport 12345 -j DNAT --to 192.168.1.5:12345
iptables -t nat -I PREROUTING -i tun+ -p udp --dport 12345 -j DNAT --to 192.168.1.5:12345

Troubleshooting

Try the following:

Look at the OpenVPN logs under Status » OpenVPN.
Assign a different IP address to your router (in case of conflict with other devices) under Setup » Basic Setup.
Check that you correctly followed all of the instructions.
Restart the router.