Siemens C2-010 - Manual (Page 31)

ADSL2+ Router User’s Guide
5-5
5.4 Outbound IP Filter Configuration
Packet filtering is a basic security measure that should be used on any network that is exposed to a
security risk. A packet filter system examines data packets and scrutinizes them in order to control network
access. Filtering rules determine whether packets are passed through the Router from either side of the
gateway. The rules are created and controlled by the network administrator and can be precisely defined.
These rules are used to block access to the LAN from outside the network and/or to deny access to the WAN
from within the network. The Router uses filtering rules to examine data packet headers for specific
information. Packets passing through the Router that do not meet the criteria specified by the rule set are
dropped.
Effective implementation of packet filtering requires detailed knowledge of network services and
communication protocols. An overly complicated filtering scheme can adversely affect the Router’s
performance, while an inadequate set of rules may needlessly compromise security.
This Router has two fields to configure for filtering which are Outbound and Inbound Filters.
Figure 5-5. Outbound IP Filter menu
This window will aid the use in configuring filters for IP addresses. This will deny specified LAN IP
addresses or specific ports associated with these LAN IP address from accessing the Internet. Well known
ports have already been previously set in the IP Filters List and can be modified by clicking their
corresponding edit icon, and simple adding an IP address to the configuration. To access this screen, click
the Advanced tab along the top of the configuration window and then the Filters tab to the left hand side.