Hello,
In case, the NTP feature was installed, after installation, it is important to restart the client machine to enable the NTP (Firewall) component.
If the NTP feature was not installed with the package, you can follow the Autoupgrade process to reinstall the feature -
Upgrading clients by using AutoUpgrade in Symantec Endpoint Protection
http://www.symantec.com/docs/HOWTO80780
How to change the Symantec Endpoint Protection (SEP) client feature set from SEPM? How to modify the SEP client installation from the Console?
http://www.symantec.com/docs/TECH203923
Hope that helps!!