The following registry key controls Network Threat Protection (NTP). It can be modified to enable/disable the Symantec Endpoint Protection firewall, or be queried for it status.
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\SMC\smc_engine_status
If the value of smc_engine_status is "0" that means NTP is Disabled
If the value of smc_engine_status is "1" that means NTP is Enabled
NOTE: Changing this value to enable or disable the firewall requires a restart of the computer.
NOTE: If the NTP component is not installed, the smc_engine_status value will continue to show a value of 1.
NTP component is not installed, the Teefer2 registry Key will not be present at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Teefer2