macos: cisco vpn docs

osx/vpn_mac.markdown

 How to setup VPN on macOS
 =========================
 
-Please follow install the Cisco Secure Client according to the [documentation](https://unlimited.ethz.ch/display/itkb/VPN) of the central IT services.
+In the past, we documented how to use the built-in VPN of the macOS System Preferences. This method will stop working in Nov/Dec 2023.
 
-The previous option, to use the built-in VPN in the System Preferences of macOS will stop working in Nov/Dec 2023.
+Please install the Cisco Secure Client according to the [documentation](https://unlimited.ethz.ch/display/itkb/VPN) of the central IT services.
+
+Open [https://sslvpn.ethz.ch](https://sslvpn.ethz.ch) in your web browser and log in with our ETH username, VPN realm (eg staff-net) and Radius password.
+
+[[!img /media/osx/vpn_mac_1.png size="450x"]]
+
+Click the `Download for macOS` button to download the Cisco installer and run it on your computer. You may also click on the `Instructions` button on the lower right corner for screenshots how to do this.
+
+After the installation, you may get a notification, that the system extension by Cisco was blocked.
+
+[[!img /media/osx/vpn_mac_2.png size="450x"]]
+
+Open the System Preferences, and manually allow the Cisco Socket Filter
+
+[[!img /media/osx/vpn_mac_3.png size="450x"]]
+
+Open your Applications folder, navigate to the Cisco subfolder, and open the `Cisco Secure Client` app.
+
+When prompted, allow the Cisco software to filter your network traffic.
+
+[[!img /media/osx/vpn_mac_4.png size="450x"]]
+
+Click on the `Connect` button and enter your VPN credentials, including the `@staff-net.ethz.ch` realm for the username, as shown below.
+
+[[!img /media/osx/vpn_mac_5.png size="450x"]]
+
+You should now see an icon in the top right menu bar, where you can check the state of the VPN connection, and disconnect when no longer needed.
+
+In particular note that you will have to re-renter your Radius password each time you connect VPN.