D-Link DSL-504 Product Manual - Page 24

DSL-504 ADSL Router User's Guide Port Redirection Window The Port Redirection feature of the Router is used in conjunction with NAT to improve security and efficiency. For example, this can be used to direct HTTP packets to a designated HTTP server as a form of firewall protection for the LAN. Other common applications might include directing incoming SMTP packets to an Email server. Click Add in the Port Redirection window to access the Redirect Port window pictured below. Redirect Port Window The Redirect Port window presents five entry fields. The first field, Comment can be used to assign an appropriate name to the new route, for our example we will use the name HTTP Server. In the Internet Port field enter the designated TCP or UDP protocol port number for the particular protocol packet you wish to redirect. In our example an incoming HTTP packets use port 80. The local port is the port used by the designated host on the LAN. In this case an HTTP server, conventionally port 8080 is used for this purpose. Choose the protocol either TCP or UDP from the pull-down Protocol menu. HTTP is defined within TCP. In the Local Computer field supply the IP address of the local designated host computer or device. Using our example you would enter the IP address of the HTTP server. Advanced Filter/Firewall The Router features IP address filtering for improved network security. Incoming or outgoing IP packets can be blocked and discarded. This allows you to restrict communications from specific outside global IP addresses from entering your network. You may also use it to restrict any specific host on the LAN from 18