To turn a Linksys router into a switch you have to turn off the settings within the device that allow it to act as a router. In doing so, you allow the Linksys to broadcast the same signal as the main router thus allowing your computers to connect to the Linksys as if it were connecting to the main router on the network. This creates a much larger and stable network for your home or business.
Tether the Linksys router to a computer with a Cat5 Ethernet cord by plugging one end of the cord into LAN jack 1 on the back of the router and the other end into the Ethernet jack on the back of the computer. Access the GUI (router settings) by typing 192.168.1.1 into a web browser. Enter "admin" into the user name and password field. On some Linksys routers, the password is left blank.
Disable the DHCP server located on the "Basic Setup" page of the GUI. Change the "Local IP address" to 192.168.1.2. Every piece of equipment on a network needs a unique IP address. Select "Save Settings."
Change the SSID on the "Wireless" section of the GUI to match the main router on the network. However, you can use a different name for the SSID if you choose. If you use a different SSID you must create a network connection on your computer for both routers to seamlessly connect.
Change the pass phrase on the "Wireless Security" tab to match the main router's pass phrase. Again, you can use a different pass phrase but you must create a network connection for both routers if you do so.
Select "Update Settings" to save the router changes.
Disconnect the cord between the router and the computer. Plug one end of the cord into one of the LAN jacks located on the back of the main router. Plug the other end of the cord into the WAN jack on the back of the Linksys router you converted into a switch.