When utilizing Parallels Desktop to operate a Windows virtual machine in shared network mode, Cisco AnyConnect VPN on the Mac side can lead to a potential disruption of internet connectivity within the Windows guest OS.
Fix the issue
To address the issue of Windows 11 in shared network mode losing internet connection when the Cisco AnyConnect VPN is turned on the host side, follow the steps below:
On your Mac, locate and open the Cisco AnyConnect Secure Mobility Client application in the Applications Folder.
Within the Cisco AnyConnect client interface, click on the "Preferences" option. You can find this option represented by a cogwheel icon, usually positioned in the bottom left corner of the client window.
In the Preferences menu, look for the option Allow local (LAN) access when using VPN (if configured) and make sure it is checked.
Enabling this option allows your Windows 11 running in shared network mode to maintain internet connectivity even when the Cisco AnyConnect VPN is active on the host machine.
After checking the option, close the Preferences window and proceed to use the virtual machine within Parallels Desktop.