When you use the Virtual Server, Port Forwarding, or Remote Administration features to open specific ports to traffic from the Internet, you could be increasing the exposure of your LAN to cyberattacks from the Internet.
In these cases, you can use Inbound Filters to limit that exposure by specifying the IP addresses of internet hosts that you trust to access your LAN through the ports that you have opened. You might, for example, only allow access to a game server on your home LAN from the computers of friends whom you have invited to play the games on that server.
Inbound Filters can be used for limiting access to a server on your network to a system or group of systems. Filter rules can be used with Virtual Server, Gaming, or Remote Administration features. Each filter can be used for several functions; for example a "Game Clan" filter might allow all of the members of a particular gaming group to play several different games for which gaming entries have been created. At the same time an "Admin" filter might only allows systems from your office network to access the WAN admin pages and an FTP server you use at home. If you add an IP address to a filter, the change is effected in all of the places where the filter is used.
Below is a list of each option with a description of its use:
Add/Edit Inbound Filter Rule
Here you can add entries to the Inbound Filter Rules List below, or edit existing entries.
Enter a name for the rule that is meaningful to you.
The rule can either Allow or Deny messages.
Source IP Range
Define the ranges of Internet addresses this rule applies to. For a single IP address, enter the same address in both the Start and End boxes. Up to eight ranges can be entered. The Enable checkbox allows you to turn on or off specific entries in the list of ranges.
Saves the new or edited Inbound Filter Rule in the following list. When finished updating the Inbound Filter Rules List, you must still click the Save Settings button at the top of the page to make the changes effective and permanent.
Inbound Filter Rules List
The section lists the current Inbound Filter Rules. An Inbound Filter Rule can be changed by clicking the Edit icon, or deleted by clicking the Delete icon. When you click the Edit icon, the item is highlighted, and the "Edit Inbound Filter Rule" section is activated for editing.
In addition to the filters listed here, two predefined filters are available wherever inbound filters can be applied:
Permit any WAN user to access the related capability.
Prevent all WAN users from accessing the related capability. (LAN users are not affected by Inbound Filter Rules.)