D-Link DSL-500 User Manual page 46

DSL-500 ADSL Router User's Guide
Packet filtering can be used in conjunction with NAT, port redirection and proxy servers to help provide basic
firewall protection. However, these measures do not address many security issues and should be used as only one
part of an overall network security strategy. It is important to remember that IP packet filtering examines only
the packet header and is not concerned with application information. Therefore, packet filtering does not protect
against higher-level security threats that may operate at the application or other level.
Filtering rules can be precisely defined based upon source and destination IP address, as well as port and
protocol information. Up to four filter sets can be used; each set contains up to sixteen filtering rules subsets.
Filter & Firewall Menu 1
The first Filter & Firewall menu lists the four filtering sets, each followed by an identifying comment. Below the
list are two drop-down menus. The filtering sets are sets of filtering rules defined in the menus shown below.
When you are finished defining the rules for each set, use the If not matched menu to select Pass or Block for
all the sets listed. From the IP Filter menu, select enabled or disabled to enable or disable the listed filtering
sets. When all the changes are made to the sets as you want them, click on the OK button. You can save the sets
and reboot the system now or continue to make other changes.
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