An easy to use tool to connect to NordVPN services for Linux. It's a single C++ binary and does not require any additional setup except that OpenVPN must be installed. The feature set is very limited. The tool does not modify any network or system settings. This means it does not change DNS servers nor does it disable IPv6 for leakage prevention unless you set it manually or provide scripts for OpenVPN as described later on.
NordVPN configuration files are downloaded and kept in memory. The OpenVPN configuration file for the selected server and the credentials file are written to /tmp/nordc and are deleted when the nordc process terminates.
Download the binary archive and extract the nordc executable anywhere you want, e.g. /usr/local/bin. The tool does require sudo privileges. At least your NordVPN username and password must be provided:
sudo nordc -v -u user -p password
randomly chooses a country and connects to a server meeting the load requirements. It will take a few seconds because the configuration files are downloaded. -v gives verbose output and may be ommitted.
It is probably better to provide a country to connect:
sudo nordc -v -u user -p password de
connects to a server in Germany meeting the load requirements.
sudo nordc -v -u user -p password de it
randomly chooses one country, Germany or Italy, and connects to a server there that meets the load requirements.
The option -s lets you provide a specific server to connect:
sudo nordc -v -s -u user -p password de961.nordvpn.com
nordc finds the least busy servers, i.e. the servers with the minimum load factor value while respecting a tolerance specified by the --loadtolerance option (0 to 100, default is 5). E.g., if the minimum load factor is 20 and the tolerance is 5, a server with a load factor of 24 is acceptable and will be taken into account. From the list of servers meeting these requirements, one will be chosen randomly. It's possible to provide a maximum acceptable load factor with the --maxload option (0 to 100, default is 70). Servers with a load factor above the maximum will be ignored. If no servers with a load factor below the maximum are available, the least busy server is selected. The tolerance value is ignored in this case.
Normally nordc starts openvpn and waits for its termination in the foreground. You can drop the connection by typing CTRL + C in the console or by killing either the nordc or openvpn process. It's possible to start openvpn in daemon mode with -d:
sudo nordc -v -d -u user -p password de
nordc will terminate immediately after starting openvpn. The openvpn process must be killed to drop the connection:
killall --wait --verbose --signal SIGINT openvpn
openvpn is called with the command line options --config, --auth-user-pass and --daemon in daemon mode. nordc passes all options directly to openvpn specified with -t (or --passthrough):
sudo nordc -v -u user -p password -t '--ping 5' de
adds --ping 5 to the openvpn call options.
This can be used to provide scripts for changing DNS settings when the connection is established and terminated with the openvpn --up and --down options:
sudo nordc -v -u user -p password -t '--script-security 2 --up ./myupscript.sh --down ./mydownscript.sh' de
--script-security 2 is necessary for openvpn to execute user scripts. No scripts are provided by the nordconnector project at the moment, however.
The released binary is compiled and statically linked for 64Bit x86 architecture and should run under most modern Linux distributions. If not, you can try to build it yourself. nordc is written in C++ 11 and uses CMake and Conan (https://conan.io/). Two build variants are available: Locally and in a docker container.
For the local build, CMake and Conan must be installed. Simply call ./build.sh in the main branch. The release binary is located under build/Release.
There are no installation prerequisites for the docker build (except for docker, of course). ./docker_build.sh creates the docker image and triggers the build. The project directory is mounted in the container. The release binary is located under dockerbuild/Release. The docker build installs everything from scratch and takes much longer but provides a clean and reproducible build environment.
nordc --help prints all available options:
nordc version 2.0.0, build time Mar 6 2024 19:14:34
Usage:
nordc [OPTION...] list of countries to connect (separated by blank), if -s is provided a specific server by name
-s, --server connect to a specific server by name, otherwise the server is chosen based on a list of countries
-d, --daemon run openvpn in daemon mode
-h, --help Print help
-e, --version Print version
-o, --ovpn arg Url to retrieve openvpn server configuration (default: https://downloads.nordcdn.com/configs/archives/servers/ovpn.zip)
-a, --stat arg Url to retrieve server statistics (default: https://api.nordvpn.com/v1/servers?limit=3000&filters[servers.status]=online&fields[servers.hostname]&fields[servers.load])
-u, --user arg User
-p, --password arg Password
-t, --passthrough arg command line options directly passed to openvpn
-l, --loadtolerance arg acceptable load tolerance (0 to 100) (default: 5)
-m, --maxload arg maximum acceptable load (0 to 100) (default: 70)
-v, --verbose Verbose output