ZyXEL Communications 50 Network Card User Manual


 
ZyWALL 50 Internet Security Gateway
15-18 Filter Configuration
15.6 Applying a Filter and Factory Defaults
This section shows you where to apply the filter(s) after you design it (them). Sets of factory default filter
rules have been configured in menu 21 to prevent NetBIOS traffic from triggering calls, and block
incoming telnet, FTP and HTTP connections.
If you do not activate the firewall, it is advisable to apply these default filters as
shown next.
15.6.1 LAN traffic
LAN traffic filter sets may be useful to block certain packets, reduce traffic and prevent security breaches.
Go to menu 3.1 (shown next) and enter the number(s) of the filter set(s) that you want to apply as
appropriate. You can choose up to four filter sets (from twelve) by entering their numbers separated by
commas, e.g., 3, 4, 6, 11. Input filter sets filter incoming traffic to the ZyWALL and output filter sets filter
outgoing traffic from the ZyWALL. The factory default set, NetBIOS_LAN, can be inserted in the protocol
filters field under Input Filter Sets in menu 3.1 to block NetBIOS traffic to the ZyWALL from the LAN.
Figure 15-15 Filtering LAN Traffic
15.6.2 Remote Node Filters
Go to menu 11.5 (shown below – note that call filter sets are only present for PPPoE encapsulation) and
enter the number(s) of the filter set(s) as appropriate. You can cascade up to four filter sets by entering their
Menu 3.1 – LAN Port Filter Setup
Input Filter Sets:
protocol filters= 2
device filters=
Output Filter Sets:
protocol filters=
device filters=
Press ENTER to Confirm or ESC to Cancel:
Apply default filter
2 here.