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Bug in openvpn version 2.5rc2

Despite a successful VPN connection, most destination addresses are no longer accessible.
The error occurs if the VPN connection was established over IPv6. IPv4 traffic is bypassed by the VPN tunnel.
The log of the openvpn client says "unable to redirect IPv4 default gateway -- Cannot obtain current remote host address".
IPv6 addresses are still reachable.

The bug affects all operating systems, but for most OS an update has already been provided. Affected are currently (16.10.2020) still Android devices.

As workaround you can use the following profiles. These restrict the VPN connection to IPv4.


I am not able to connect to the VPN-Server of the Universitiy of Siegen

Please test if you have a working internet connection. Try visiting a website of your choice. If this does not work, it is not a VPN problem.
If you have a working Internet connection, the operator of the network in which your terminal device is located may block the necessary VPN ports in his firewall (udp/443 and udp/1194).
In this case, please download the following profiles and import them into your OpenVPN application.

Windows: uni-tcp and admin-tcp 

All other OS: uni-tcp und admin-tcp 

However, it is recommended to use the udp profiles by default, unless you are experiencing the above mentioned problems.

Windows 10 - The connection terminats immediately

Take a look into the log of the OpenVPN application. Does the log contain the following entries?

There are no TAP-Windows adapters on this system.  You should be able to create a TAP-Windows adapter by going to Start -> All Programs -> TAP-Windows -> Utilities -> Add a new TAP-Windows virtual ethernet adapter.

Exiting due to fatal error

This means that the TAP Driver has not been installed. Uninstall OpenVPN (Start -> System Settings -> Apps; choose OpenVPN and tap on uninstall. Afterwards do a fresh install of OpenVPN.

Problems with disabled IPv6 on Linux

If you have disabled IPv6 on your system, you will get an error when connecting (only affects the start from the console). Either you activate IPv6 on your system or you edit your profile file and add the two lines

pull-filter ignore "ifconfig-ipv6"
pull-filter ignore "route-ipv6"

Problems updating IOS from OpenVPN Connect version 1.2.9 to 3.0.0

The existing configuration files no longer work. Please delete the old profiles (uni,admin etc.) and reinstall them.

IOS 9 - parallel operation of IPv4 and IPv6 does not work.

Due to a bug in IOS 9 the IPv4 traffic is routed past the tunnel. This leads to a situation in which protected contents of the university cannot be accessed despite a VPN connection being established.
Workaround is the deactivation of IPv6 in the IOS App (Settings ->IPv4-ONLY Tunnel).

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