Mac clients for Symantec Endpoint Protection Cloud do not support Mac OS X 10.11 (El Capitan).
As of macOS 10.13, you must authorize the Symantec Endpoint Protection kernel extension after installation for Symantec Endpoint Protection to fully function. You are prompted during the client installation to do it if needed. If you do not do it during the client installation, go to System Preferences > Security & Privacy, and click Allow. Neither Symantec Endpoint Protection nor the Mac operating system continue to remind you that you must do this. You only need to authorize the kernel extension once during the life of the computer's operating system. If you uninstall and reinstall the client, you don't need to reauthorize the kernel extension. If you have Symantec Endpoint Protection 14 and then upgrade to macOS 10.13, you don't need to reauthorize the kernel extension. However, if you reinstall the operating system, you need to reauthorize the kernel extension. See About authorizing kernel extensions for Symantec Endpoint Protection for macOS 10.13.
Kext notarization was added in macOS 10.14.5. If you install a client version earlier than 14.2 RU1 (refresh) on macOS 10.14.5, or upgrade the operating system to macOS 10.14.5 with an earlier version of Symantec Endpoint Protection already installed, you may experience issues. See Endpoint Protection 14.2 RU1 and kext notarization for macOS 10.14.5.
Intrusion Prevention (IPS) is available in version 12.1.4 and later.
Device Control is available in version 14 and later. You can only enable Device Control for managed clients.
Mac client versions earlier than 14.2 do not include a firewall.
IPS was introduced in version 12.1.4, but broader firewall support (e.g. traffic rules) and feature parity with the Windows product was not included until version 14.2 and later. This firewall is only available to managed clients.