How to set up AdGuard VPN for Linux on a Keenetic router

System requirements

AdGuard VPN for Linux, also known as AdGuard VPN CLI, requires at least 22 MB of free storage space on your router’s built-in memory or external USB after other necessary packages are installed.

1. Make sure that SSH is enabled on your router

The SSH client is used to send commands to your router from your computer.

To run the SSH server, the SSH server system component must be installed in the Keenetic. You can do this on the General system settings page in the Component options section by clicking the Component options button. Search for SSH server and install it. This will update your Keenetic OS.

Once the component is installed, the SSH server will be turned on automatically.

To see how to set up SSH server to have optimal security settings, visit the Keenetic Wiki.

2. Determine your router’s IP address

The default IP address for most routers is 192.168.1.1 or 192.168.0.1. If you’ve changed the IP address or if you’re unsure, you can find it by checking the IP configuration on a connected device.

On Windows

1. Open Command Prompt:

ipconfig

1. Look for the Default Gateway under your active network connection. This is your router’s IP address.

On macOS and Linux

1. On Linux, open Terminal and run this command:

   ip route | grep default

   Or this on Mac:

   route -n get default

2. Look for the default entry. The IP address next to it is your router’s IP address.

3) Use an SSH client to connect to the router

You’ll need an SSH client. Most Linux and macOS systems come with an SSH client pre-installed. For Windows, you can use PowerShell, the built-in SSH client in Windows 10/11, or a third-party application like PuTTY.

Built-in SSH client (Linux, macOS, and Windows 10/11)

1. Open Terminal or PowerShell.

2. Run the SSH command:

ssh admin@192.168.1.1

Replace 192.168.1.1 with your router’s IP address.

1. If this is your first time connecting to the router via SSH, you’ll see a message like this:

   The authenticity of host '192.168.1.1 (192.168.1.1)' can't be established.
   ECDSA key fingerprint is SHA256:...
   Are you sure you want to continue connecting (yes/no/[fingerprint])?

Type yes and press Enter.

1. Enter the router’s password when prompted. The default username is root and the default password is keenetic.

PuTTY (Windows 8 and earlier)

1. Download and install PuTTY from the official website.

2. Open PuTTY.

3. In the Host Name (or IP address) field, enter your router’s IP address (e.g., 192.168.1.1)

4. Ensure the Connection type is set to SSH.

5. Click Open.

6. When the Terminal window opens, log in. The default username is root and the default password is keenetic.

Once logged in, you can use various commands to interact with your router’s Linux-based operating system.

4. Install OPKG Entware

In Keenetic models equipped with a USB port (except Keenetic 4G), you can use the OPKG package manager. It allows you to install third-party software packages to expand routers capabilities.

Starting with version 3.7, for some Keenetic models, it is possible to write OPKG Entware to the UBIFS partition of the router's NAND flash memory, i.e. to the built-in memory of the router. Follow the steps below to install the Entware repository package system on a USB drive or in the router’s internal memory.

How to install OPKG Entware on a USB drive

It is possible to install OPKG packages on the Keenetic models with USB ports that support USB flash drives. These are: KN-1410, KN-1710/1711, KN-1010/1011, KN-2510, KN-2410, KN-1810, KN-1910, KN-2310, KN-2010, KN-2110, KN-2610, KN-2710.

For detailed instructions, visit the official Keenetic Wiki.

How to install OPKG Entware in the router’s internal memory

This method will work with the following models: KN-1010/1011, KN-1810/1811, KN-1910, KN-2010, KN-2110, KN-2310, KN-2410, KN-2510, KN-2610, KN-2710, KN-3810, KN-3610 with the KeeneticOS version 3.7 and later.

For detailed instructions, visit the official Keenetic Wiki.

If your router doesn’t support installing packages on its internal memory, follow the instructions for installing packages on a USB drive.

5. Install AdGuard VPN CLI

In your SSH client, execute the following code to install the packages required for AdGuard VPN CLI:

opkg install curl sudo ca-certificates

Go to the /opt folder by typing /cd opt and run the AdGuard VPN CLI installation script:

curl -fsSL https://raw.githubusercontent.com/AdguardTeam/AdGuardVPNCLI/master/scripts/release/install.sh | sh -s -- -v

When asked “Would you like to link the binary to /usr/local/bin?“, reply n and run this line:

ln -s /opt/adguardvpn_cli/adguardvpn-cli /opt/bin

6. Set up AdGuard VPN CLI

1. Log in to your account

   To use AdGuard VPN for Linux, you need an AdGuard account. You can sign up or log in on our website or in Terminal.

   Before logging in, go to Terminal and make sure you are in the right shell interface. If you can see the following text:

   KeeneticOS version 4.01.C.7.0-1, copyright (c) 2010-2024 Keenetic Ltd.
   
   THIS SOFTWARE IS A SUBJECT OF KEENETIC LIMITED END-USER LICENCE AGREEMENT. BY USING IT YOU AGREE ON TERMS AND CONDITIONS HEREOF. FOR MORE INFORMATION PLEASE CHECK https://keenetic.com/legal

   Run this command to exit into the shell needed for the next steps:

   exec sh

   If you see the following text, you can continue the setup:

   BusyBox v1.36.1 (2024-08-08 16:11:23 UTC) built-in shell (ash)
   
   / #

   To sign up or log in, type:

   adguardvpn-cli login

2. Connect to VPN

   For Keenetic routers, be sure to import the SSL certificate and select a folder for the user directory by running this command before connecting:

   export SSL_CERT_FILE=/opt/etc/ssl/certs/ca-certificates.crt
   export HOME=/opt/home/admin

   This must be done before each session.

   Select a VPN server location that best suits your needs.

   In general, the closer the server is to you, the faster the connection.

   To view available locations, type:

   adguardvpn-cli list-locations

   To connect to a specific location, type:

   adguardvpn-cli connect -l LOCATION_NAME

   Replace LOCATION_NAME with the city, country, or ISO code of the location you want to connect to.

   For quick connect, type:

   adguardvpn-cli connect

   AdGuard VPN will choose the location with the lowest ping and remember it for future quick connections.

3. Adjust your settings

   Get a list of all available AdGuard VPN commands and customize the VPN client to your needs.

   To view all commands, type:

   adguardvpn-cli --help-all

4. Enter yes when asked “Would you like to set default routes in TUN mode?”

AdGuard VPN CLI will create a tun0 interface for VPN tunneling

7. Set up firewall rules

This step is designed to configure firewall rules on a Keenetic router to route traffic through AdGuard VPN.

1. Install iptables by running this command via SSH:

   opkg install iptables

   This line installs the iptables package, which is a tool for managing network packet filtering rules on Linux systems.

2. Create a new shell script by running the following command:

   
   cat << 'EOF' > /opt/etc/ndm/netfilter.d/001-adguardvpn.sh
   #!/opt/bin/sh
   for ipt in iptables ip6tables; do
       $ipt -D FORWARD -j ADGUARD_FORWARD || true
       $ipt -F ADGUARD_FORWARD || true
       $ipt -X ADGUARD_FORWARD || true
       $ipt -N ADGUARD_FORWARD
       $ipt -I FORWARD -j ADGUARD_FORWARD
       $ipt -A ADGUARD_FORWARD -i br0 -o tun0 -j ACCEPT
   done
   EOF

   And make it executable:

   chmod +x /opt/etc/ndm/netfilter.d/001-adguardvpn.sh

   If you have more brX interfaces, make sure to include them in the script as well to route their traffic. Alternatively, make sure to specify a different routing rule for those interfaces.

This will create a new shell script named 001-adguardvpn.sh in the /opt/etc/ndm/netfilter.d/ directory, which is where network-related scripts are typically stored on a Keenetic router.

The script creates a custom firewall rule to ensure that traffic from your LAN (br0) is routed through the AdGuard VPN interface (tun0). It first cleans up any previous rules related to this configuration, then sets up new rules to direct the traffic appropriately.

8. Set up automatic launch for AdGuard VPN CLI

The following script is designed to automatically establish a VPN connection using AdGuard VPN on your Keenetic router when the WAN interface becomes available (e.g., after a reboot or reconnecting to the Internet).

Run the following command:

cat << E0F > /opt/etc/ndm/wan.d/001-adguardvpn.sh
#!/opt/bin/sh
export SSL_CERT_FILE=/opt/etc/ssl/certs/ca-certificates.crt
export HOME=/opt/home/admin
/opt/adguardvpn_cli/adguardvpn-cli connect &
exit 0
E0F

And make it executable:

chmod +x /opt/etc/ndm/wan.d/001-adguardvpn.sh

The script named 001-adguardvpn.sh will be saved to /opt/etc/ndm/wan.d/.

It will start AdGuard VPN when Internet is connected.

Reboot your router to finish setup.

Congrats! Now you have a router secured with AdGuard VPN.