Hi,
The Symantec Endpoint Protection firewall uses firewall policies and rules to allow or block network traffic. The Symantec Endpoint Protection includes a default Firewall policy with default firewall rules and firewall settings for the office environment. The office environment is normally under the protection of corporate firewalls, boundary packet filters, or antivirus servers. Therefore, it is normally more secure than most home environments, where limited boundary protection is available.
About the Symantec Endpoint Protection firewall
http://www.symantec.com/docs/HOWTO55247
Available Videos:
Allow & Block websites using SEP firewall
https://www-secure.symantec.com/connect/videos/allow-and-block-websites-using-symantec-endpoint-protection-firewall
How To Block Internet addres via Sep Manager Firweall Rule
https://www-secure.symantec.com/connect/articles/how-block-internet-address-sep-manager-firewall-rule