1. technology and computing
2. networking
3. vpn and remote access

OpenVPN4UCS
How-To / First Steps
version 0.2
OpenVPN4UCS >= 0.7
Page 1 of 8
Disclaimer
Please be aware that OpenVPN is a powerful tool, which can be used for
securing communication channels in a great variety of ways and use
cases. The integration package OpenVPN4UCS focuses on a common
one: providing secure access for users to a specific network / domain,
which is in this case managed by an Univention Corporate Server domain
controller. This also means that the integration package is not a graphical
toolset for all possible setups OpenVPN could be used for.
As OpenVPN4UCS is provided for free at no cost, there is no warranty
provided with it, especially not for the packages provided by the operating
system itself.
To ensure the stability and usability of this integration package we
(bytemine GmbH) invite you to get in touch with us, if you experience any
issue, have questions or just want to give us general feedback.
If you are in need of further assistance, bytemine GmbH offers high quality
OpenVPN and UCS consultency.
Furthermore this HowTo is not meant as a replacement for fundamental
VPN and IT security knowledge. People (administrators) using this software
should have a general idea on IT security and Linux based systems.
End of disclaimer
Page 2 of 8
Introduction
This guide will show how to use the OpenVPN4UCS integration module. A
typical scenario will be taken as an example and its configuration shown
and illustrated.
Prerequisites
•
•
•
Univention Corporate Server, at least version 3.1
Administrative access to the Univention Management Console (UMC)
OpenVPN4UCS installed via the App Center
Scenario
A common usage for a VPN setup is to empower road warriors to gain access to
the company network, although working from a remote location.
This can be achieved by setting up an OpenVPN server (also called vpn
concentrator) on a UCS memberserver, and distributing certificates and
configurations to the user.
Setup
Preparations
•
•
Log in to the Univention management console
Install OpenVPN4UCS via the App Center
Page 3 of 8
Server setup
•
•
Navigate inside the UMC to the member server that shall function as
OpenVPN concentrator.
Select “Advanced settings” and unfold the OpenVPN section
Page 4 of 8
•
•
Edit the settings according to your desired setup:
• The OpenVPN server address is used by clients to connect to the
OpenVPN server
• The OpenVPN transfer network can be left on the default value; just
change it if it collides with other networks involved.
• The OpenVPN port has to be open from the Internet, please adjust
your firewall accordingly.
• Check the option “OpenVPN server active” to enable the OpenVPN
services on the server.
• Check the option “OpenVPN duplicate” if users are allowed to
connect with multiple devices simultaneously.
• Check the option “OpenVPN redirect gateway” if the clients
computer shall route all traffic through the VPN network.
Save the changes. If you selected the “OpenVPN server active” option the
OpenVPN process will be started on the member server within a short
period.
Page 5 of 8
User setup
•
•
•
Navigate inside the UMC to the user that you want to use VPN access
Select “Advanced settings” and unfold the OpenVPN section.
Check the option “OpenVPN account”.
•
Certificates and client configuration (for Windows and Linux systems) are
written as a zip file to the users home on the UCS master.
/home/<username>/openvpn-<member server>-<username>.zip
Disabling the option “OpenVPN account” in the user section will revoke the users
certificate; the user is not allowed to connect with the VPN anymore. Revocations
are synchronized with the servers multiple times a day.
Enabling this option again will create a new ready2go package for the user; the
old certificate stays invalid.
Page 6 of 8
OpenVPN setup on client side
As there are many different operating systems and VPN clients existing this
document will only describe the configuration of the OpenVPN client on a
Windows 7 system.
Assuming the OpenVPN software has already been installed:
• Copy the OpenVPN4UCS ready2go package from your home directory to
the OpenVPN\config directory and extract it there.
• Delete the .ovpn file that does not start with “win-”
• Open the OpenVPN GUI
• Choose either “Connect” if this is the only OpenVPN connection, or
• Choose the OpenVPN connection to the UCS member server if
multiple configurations exist, and click “Connect”
• Enter your username and password (same credentials as for the
UCS)
Page 7 of 8
Page 8 of 8