Firewalls :
 

Most people today have firewalls in place providing some amount of protection from the outside world. Protection, however, does not necessarily mean you are covered. Before, you get too comfortable; you should evaluate your firewall for configuration flexibility. You should also review the number and types of firewalls you have deployed. In most enterprise networks, a single firewall protecting you from the Internet is not sufficient. Finally, unless you have someone dedicated to reviewing the firewall logs (assuming your firewall creates a log file), then you may be missing key information you need to insure that your firewall remains as effective as you once thought it was.

 
For more product specific details, see
 
Firewall Security » Checkpoint