After logging in, the setup screen opens, as shown in the figure. The setup screen has tabs that help you configure the router. You must click Save Settings at the bottom of each screen after making any changes.

All routers that are designed for a home or a small business are preconfigured with basic settings. These settings can be located under different tabs depending on the make and model of the router. It is good practice to make changes to the following default settings.

While some default settings should be changed, others are best left alone. Most home or small business networks share a single Internet connection provided by the ISP. Routers in this type of network receive public addresses from the ISP, which allows the router to send and receive packets to and from the Internet. The router provides private addresses to local network hosts. Because private addresses cannot be used on the Internet, a process is used for translating private addresses into unique public addresses. This allows local hosts to communicate over the Internet.

Network Address Translation (NAT) is the process used to convert private addresses to Internet-routable addresses. With NAT, a private (local) source IP address is translated to a public (global) address. The process is reversed for incoming packets. The router is able to translate many internal IP addresses into public addresses, by using NAT.

Only packets destined for other networks need to be translated. These packets must pass through the gateway, where the router replaces the private IP addresses of the source hosts with the public IP addresses of the router.

Although each host on the internal network has a unique private IP address, the hosts share Internet routable addresses that have been assigned to the router by the ISP.

When using the configuration screens of the E2500 router, click the Help tab to see additional information about a tab. For information beyond what is shown on the help screen, consult the documentation.