Most cable modems are designed to connect directly to a single computer with an Ethernet cable. This is because most cable modems are designed to accept only a single IP address from the Internet Service Provider (ISP). If multiple computers wish to simultaneously access the Internet through the cable modem, such as a Mac and a PC, a router must be connected to the cable modem to share the connection to all the computers.
Power off the cable modem. If your Internet provider also provides phone service, temporarily remove the battery from the cable modem. Note that only cable modems that also provide phone service contain a removable battery. Cable modems that only provide Internet service don't contain a removable battery.
Plug one end of an Ethernet cable to the port on the cable modem. Plug the other end of the cable into the "Internet" port on the router.
Power on the cable modem and replace the battery, if necessary. Wait approximately one minute for the cable modem to synchronize.
Power on the router.
Connect both the Mac and the PC to the router via either wired Ethernet or wireless, depending on the type of router installed. Home routers are configured by default to automatically share the Internet connection with no additional configuration required.
- Most routers can be configured by opening a Web browser and entering "192.168.1.1" (without quotes) in the address bar. Additional configuration is only necessary under special circumstances, such as changing wireless settings.
- Thomas Northcut/Photodisc/Getty Images