As part of a software upgrade to the TUvpn server, support for older encryption methods was removed from the VPN server software by the manufacturer. Unfortunately, we have discovered that this means that VPN connections using L2TP/IPsec from Android devices are no longer possible, as these only support older encryption methods (which are now considered very insecure).
We recommend that Android users use the Cisco Secure Client (https://play.google.com/store/apps/details?id=com.cisco.anyconnect.vpn.android.avf, opens an external URL in a new window) to connect to the TUvpn.
Unfortunately, a new installation of the older software version on the TUvpn server including reactivation of the older encryption methods represents too high a risk for the IT and information security of the TU Wien and is therefore out of the question. For use cases that cannot be covered by the Cisco Secure Client or the alternative client OpenConnect, we are currently evaluating other options.