OpenVPN Client Settings

Supported Client Platforms

The following platforms have been tested to work with our server:

  • RHEL 7, 8, 9

  • Debian 10, 11, 12

  • Ubuntu 18.04, 20.04, 22.04

  • Mac OS

  • Fedora

  • Windows 10, 11

What you need

  • OpenVPN

  • OVPN config file containing our default config and all certificates

CA Certificate

We renewed our CA certificate in September 2021. You can download it here: ca.crt


In general, the OVPN file we provide you should have all of the information you need to connect, however below are the basic settings you have:

  • server:

  • type: Certificate (TLS)

  • Advanced:

    • General -> Set virtual device type: TUN

    • Security -> Cipher: AES-256-GCM

    • TLS Authentication -> Verify peer (server) certificate usage signature:

Network Manager (Linux)


# Debian/Ubuntu:
$ apt install network-manager-openvpn-gnome

$ yum install epel-release
$ yum install NetworkManager-openvpn-gnome


  • Install the packages mentioned above

  • Open Network Manager

  • Click the + to create a new VPN connection

  • Click on Import from file..

  • Use the .ovpn file we gave you

  • There are some additional settings we recommend you change that we’re not able to do via the .ovpn file.

    • IPv4 -> DNS:,

    • IPv4 -> and select: Use this connection only for resources on its network

    • IPv6 -> IPv6 Method: Disable

  • Click on the Network Manager status bar icon and select: VPN Off -> Connect

  • Wait until connection is established

  • Check connection:

    • ip a – An IP address should be in the 10.2.*.* range via a tun0 interface.

    • ping -c 1 – You should be able to ping this IP address

Trouble shooting

Check the system logs by doing the following:

journalctl -t nm-openvpn

Systemd service (Linux)


# Debian/Ubuntu:
$ apt update
$ apt install openvpn resolvconf-admin

$ yum install epel-release
$ yum install openvpn


  • Install the packages mentioned above

  • Copy the .ovpn file we gave you as /etc/openvpn/client/osuosl.conf


For Debian/Ubuntu users: You will need to change the group from nobody to nogroup

  • Change permissions: chmod 0600 /etc/openvpn/client/osuosl.conf

  • Enable and start the OpenVPN client service:

systemctl enable openvpn-client@osuosl.service
systemctl start openvpn-client@osuosl.service
  • Check connection:

    • ip a – An IP address should be in the 10.*.*.* range via a tun0 interface.

    • ping -c 1 – You should be able to ping this IP address


Check the system logs from the service by doing the following:

journalctl -u openvpn-client@osuosl.service

Unable to connect

Our certificates were originally signed using the sha1 algorithm which is no longer supported on newer operating systems (Fedora, RHEL >= 9, Ubuntu >= 22.04, etc). To fix this, we need to renew your certificate which will be signed using sha256.

Please send an email to with the subject line: OpenVPN Certificate renewal: <Name>. We will send you an updated certificate which should fix the issue.

Tunnelblick (OS X)

Tunnelblick is a free, open source gui for OpenVPN on OS X that allows for easy control of the OpenVPN client.


Download and install Tunnelblick from the project’s downloads page.

Alternatively install the package using the Homebrew:

brew cask install tunnelblick


Tunnelblick uses a .ovpn file with your certificate and key to install a profile. If you would like to set up OpenVPN using Tunnelblick, please send an email to with the subject line: OpenVPN .ovpn file: <Name>. We will send you the file that you can easily use:

  1. Double click the USER.ovpn file we provided to install the profile in Tunnelblick.

  2. Open Tunnelblick and connect to the USER profile.


You may need to check Tunnel all IPv4 under the advanced settings for the USER profile.

OpenVPN (Windows)

OpenVPN community edition for windows uses the .ovpn file we provided.

  1. Download window openvpn client from openvpn_community_downloads page. and install. Versions 2.5 and higher should work fine. Earlier versions may also work.

  2. Create a folder in C:\Program Files\OpenVPN\config called osuosl and copy the .ovpn, .crt, and .key files provided into the folder

  3. Edit the .ovpn file sections ca, cert, key. Should have full path e.g. replacing yourname with the filename part of your crt and key files

ca "C:\Program Files\OpenVPN\config\osuosl\ca.crt"         # Server certificate
cert "C:\Program Files\OpenVPN\config\osuosl\yourname.crt" # Client certificate
key "C:\Program Files\OpenVPN\config\osuosl\yourname.key"  # Client private key

Once done with configs launch the C:\Program Files\OpenVPN\bin\openvpn-gui.exe, this should create an icon on your task bar you can right click and see OSUOSL option for connection