Netgear FVS318G FVS318G User Manual - Page 57

ProSafe Gigabit 8 Port VPN Firewall FVS318G Reference Manual Note: See "Configuring Source MAC Filtering" on page 4-24 for yet another way to block outbound traffic from selected PCs that would otherwise be allowed by the firewall. Inbound Rules (Port Forwarding) When the FVS318G uses Network Address Translation (NAT), your network presents only one IP address to the Internet and outside users cannot directly address any of your local computers. However, by defining an inbound rule you can make a local server (for example, a Web server or game server) visible and available to the Internet. The rule tells the firewall to direct inbound traffic for a particular service to one local server based on the destination port number. This is also known as port forwarding. Whether or not DHCP is enabled, how the PCs will access the server's LAN address impacts the Inbound Rules. For example: • If your external IP address is assigned dynamically by your ISP (DHCP enabled), the IP address may change periodically as the DHCP lease expires. Consider using Dyamic DNS (under Network Configuration) so that external users can always find your network (see "Configuring Dynamic DNS (Optional)" on page 2-13. • 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 feature in the LAN Groups menu (under Network Configuration) to keep the PC's IP address constant (see "Configuring DHCP Address Reservation" on page 3-9. • Local PCs must access the local server using the server's local LAN address. Attempts by local PCs to access the server using the external WAN IP address will fail. Note: See "Configuring Port Triggering" on page 4-27 for yet another way to allow certain types of inbound traffic that would otherwise be blocked by the firewall. Firewall Protection and Content Filtering 4-5 1.1 November, 2009