The official guide is obviously terrible at doing its job for linux, so I thought I'd write a tiny guide on how to do this myself. I use Arch, so this will be arch-centric. If you use other distros, lookup your version of the same packages as the ones Arch ships, but they should be fairly generic.
Install openconnect. For arch, this is pacman -Syu openconnect.
Once you did, you can connect to the VPN through:
sudo openconnect -protocol=gp --csd-wrapper=/usr/lib/openconnect/hipreport.sh vpnaccess.unito.itA bit about the options:
-protocol=gp: Unito uses the GlobalProtect protocol, hencegp.--csv-wrapper=/usr/lib...: The unito VPN asks for a 'hipreport'. This provides it. No idea what it is, or why.vpnaccess.unito.it: The url of the vpn portal.
It should ask you to log in. Use your credentials for unito.it. Note that VPN access is for authorized users only. If you
did not ask for authorization, the portal will let you login (?) but a firewall will (silently) block all outgoing packages
for your UniTO connections, so it would be as if you are not connected at all.
If you want to use a GUI, NetworkManager comes to the rescue. Install networkmanager-openconnect and open NetworkManager.
Click on "New Connection" (usually a big + below your list of networks), scoll down and select "PAN Global Protect (openconnect)"
The next panel should ask you for the vpn portal URL as well as other info. If it does not, you have not installed
networkmanager-openconnect (probably). Insert the url, then save. To connect, click the connection in you connection
list. A pop-up should open asking you to log in. Select the (only) gateway, and you will be connected.
The same disclaimer for authorization-only access is valid for this methon (obviously).