Things You'll Need
Instructions
Plug your Ethernet cable into your router, and the other end into the broadband connector on the back of the Dreamcast.
Turn on the Dreamcast and insert your Dreamcast Web browser disk.
Select "OK," then select "Options" followed by "Internet Connection."
Enter in your name and your desired username and password in the appropriate boxes.
Enter "0.0.0.0" for the Internet Protocol, subnet, gateway and DNS entry options. This causes your Dreamcast to obtain IP addresses automatically for each of the entries on its own. You may now browse the Internet or play games online with your Dreamcast.