Reference Manual for the Model DG824M Wireless ADSL Modem Gateway
Protecting Your Network 4-9
Inbound Rule Example: Allowing Videoconference from Restricted Addresses
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.
Figure 4-6: Rule example: Videoconference from Restricted Addresses
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 menus so that external users can always find your network.
• If the IP address of the local server PC is assigned by DHCP, it may change when the PC is
rebooted. To avoid this, use the Reserved IP address fe at ure in the LAN IP menu to keep the
PC’s IP address constant.
• Local PCs must access the local server using the PCs’ local LAN address (192.168.0.11 in the
example in Figure 4-6 above). Attempts by local PCs to access the server using the external
WAN IP address will fail.