Motorola MG7315 User Manual page 37

The firewall lets you set your protection level through IPv4 Firewall
Protection, for example. By default, with the Low setting, all services are
allowed. If you select Medium or High protection, the firewall will block all
services except those listed in the List of Allowed Services at the bottom of
the page. Select the desired protection level, and click Save.
The higher protection levels will make it harder for attackers to penetrate
your network. You may find that if you select one of these levels, that some
Internet activities may fail. If that is the case, you may need to use a lower
level of protection during those activities.
Note that in order to play some games, you may need to turn protection off.
When enabled, Port Scan Detection and IP Flood Detection will generate
reports in the Firewall Log if they detect their respective attacks.