Security 13-17Modifying filter setsTo modify a filter set, select Display/Change IP Filter Set in the IP Filter Sets screen to display a list of filtersets.Select a filter set from the list and press Return. The Change IP Filter Set screen appears. The items in thisscreen are the same as the ones in the Add Filter screen (see “Adding filters to a filter set” on page 13-14).Deleting a filter setNote: If you delete a filter set, all of the filters it contains are deleted as well. To reuse any of these filters inanother set, before deleting the current filter set you’ll have to note their configuration and then recreate them.To delete a filter set, select Delete IP Filter Set in the IP Filter Sets screen to display a list of filter sets.Select a filter set from the list and press Return to delete it. Press Escape to exit the list without deleting thefilter set.A sample IP filter setThis section contains the settings for a filter set called Basic Firewall, which is part of the Netopia R9100’sfactory configuration.Basic Firewall blocks undesirable traffic originating from the WAN (in most cases, the Internet), but passes alltraffic originating from the LAN. It follows the conservative “that which is not expressly permitted is prohibited”approach: unless an incoming packet expressly matches one of the constituent input filters, it will not beforwarded to the LAN.Change IP Filter SetFilter Set Name: Basic FirewallDisplay/Change Input Filter...Add Input Filter...Delete Input Filter...Display/Change Output Filter...Add Output Filter...Delete Output Filter...
