This guide covers the basic Debian based guide, however, it should work the same on other distributions.
1. First, make sure you have all the dependencies on your device. You can do that by running the following command:
sudo apt-get update && apt-get upgrade
2. Get the following packages:
sudo apt-get install strongswan libcharon-extra-plugins libcharon-standard-plugins
Note: For Arch-based distributions and others, you might not have libcharon packages, as they are in the strongswan package. You can just run: pacman -S strongswan and it should be enough.
3. Edit the ipsec.secrets file with your NordVPN username and password.
sudo nano /etc/ipsec.secrets
4. Change Username with your NordVPN username, and your password with your NordVPN password. Your password has to be wrapped inside double-quotes. Notice the spaces after Username, after “:” and after EAP.
5. Once again, use the preferred text editor to enter /etc/ipsec.conf file. Do not forget root privileges since the file is write-protected from anyone except root.
sudo nano /etc/ipsec.conf
6. The following config should be like this:
conn NordVPN keyexchange=ikev2 dpdaction=clear dpddelay=300s eap_identity="USERNAME" leftauth=eap-mschapv2 left=%defaultroute leftsourceip=%config right=SERVER rightauth=pubkey rightsubnet=0.0.0.0/0 rightid=%SERVER rightca=/etc/ipsec.d/cacerts/NordVPN.pem type=tunnel auto=add
Change SERVER to the hostname of the server you are going to use, and USERNAME to your NordVPN username.
7. We recommend using the “Recommended server” utility to get the best possible server for the IKEv2 setup. You can find the utility here: https://nordvpn.com/servers/tools/
For this guide, we used the US #1019 server.
sudo nano /etc/strongswan.d/charon/constraints.conf
Inside the file change load = yes to load = no.
9. Download the NordVPN RSA certificate.
sudo wget https://downloads.nordcdn.com/certificates/root.der -O /etc/ipsec.d/cacerts/NordVPN.der
sudo openssl x509 -inform der -in /etc/ipsec.d/cacerts/NordVPN.der -out /etc/ipsec.d/cacerts/NordVPN.pem
10. Now let’s restart ipsec in order to reload all configuration files.
sudo ipsec restart
If you’ve made any typos in /etc/ipsec.conf file you’ll be notified when service will be trying to start.
11. After it’s done, you can connect by launching this command:
sudo ipsec up NordVPN
This command should show the output “Connection NordVPN has been established successfully”.
Note: if you are receiving No config named 'NordVPN' error after running the ipsec up NordVPN command, please refer to this article.
12. To disconnect, simply type:
sudo ipsec down NordVPN
13. If you have any issues with the setup, you can get the logs at this location and send to our support:
sudo cat /var/log/syslog