ZyXEL Communications 10 - Manual (Page 186)

ZyWALL 10~100 Series Internet Security Gateway
13-14 Firewalls
3. To selectively block/allow inbound or outbound traffic between inside host/networks and outside
host/networks. Remember that filters cannot distinguish traffic originating from an inside host or an
outside host by IP address.
4. The firewall performs better than filtering if you need to check many rules.
5. Use the firewall if you need routine e-mail reports about your system or need to be alerted when attacks
occur.
6. The firewall can block specific URL traffic that might occur in the future. The URL can be saved in an
Access Control List (ACL) database.