Windows – Cisco AnyConnect not Working

That greatly depends on the configuration of the server. Cisco Concentrators can speak PPTP which works on nearly every version of Windows, but it's costly in terms of performance. The number of possible connections drops to about a tenth for the server so this is rarely activated.

Furthermore there seems to be an option to enable L2TP. The documentation states that but at least for our university here no one figured out how to enable it and set it up.

You would have to ask the person maintaining the server whether one of the above options apply.

For the "usual" Cisco IPSec over UDP there is no native option in Windows, unfortunately.

This depends on the VPN server on the other side too. Older VPN Concentrators use a different protocol (IPSec over UDP/TCP) while AnyConnect tunnels through HTTPS. So it may be a configuration issue on the server side where HTTPS might not be enabled or the server is simply too old in which case you're out of luck.

There are third-party clients that support connecting to Cisco VPN servers, such as

• Shrew Soft VPN Client. I killed my machine with that back in last January, though. But maybe they have Windows 7 support by now and don't blue-screen anymore.
• vpnc which supposedly works on Cygwin too.