NETGEAR DG834v3 - ADSL Modem Router, Reference Manual

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Reference Manual for the ADSL Modem Router DG834
Protecting Your Network 4-9
v2.3, May 2007
Inbound Rule Example: Allowing Videoconferencing
If you want to allow incoming videoconferencing to be initiated from a restricted range of outside
IP addresses, such as from a branch office, you can create an inbound rule. In the example shown
in
Figure 4-6 , CU-SeeMe connections are allowed only from a specified range of external IP
addresses. In this case, we have also specified logging of any incoming CU-SeeMe requests that
do not match the allowed parameters.
Considerations for Inbound Rules
• If your external IP address is assigned dynamically by your ISP, the IP address may change
periodically as the DHCP lease expires. Consider using the Dynamic DNS feature in the
Advanced menu so that external users can always find your network.
• If the IP address of the local server computer is assigned by DHCP, it may change when the
computer is rebooted. To avoid this, use the Reserved IP address feature in the LAN IP menu
to keep the computer’s IP address constant.
• Local computers must access the local server using the computer’s local LAN address
(192.168.0.11 in the example in
Figure 4-6 above). Attempts by local computers to access the
server using the external WAN IP address will fail.
Outbound Rules (Service Blocking)
The DG834 v3 allows you to block the use of certain Internet services by computers on your
network. This is called service blocking or port filtering. You can define an outbound rule to block
Internet access from a local computer based on:
Figure 4-6