Internet Sharing

If you have cable modem or DSL service, you’re a very lucky individual. You get terrific Internet speed and an always-on connection. Too bad only one computer in your household or office can enjoy these luxuries.

It doesn’t have to be that way. You can spread the joy of high-speed Internet to every Mac (and PC) on your network in either of two ways:

  • Buy a router. A router is a little box, costing about $50, that connects directly to the cable modem or DSL box. In most cases, it has multiple Internet jacks so you can plug in several Macs, PCs, and/or wireless base stations. As a bonus, a router provides excellent security, serving as a firewall to keep out unsolicited visits from hackers on the Internet.

  • Use Internet Sharing. OS X’s Internet Sharing feature is the software version of a router: It distributes a single Internet signal to every computer on the network. But unlike a router, it’s free. You just fire it up on the one Mac that’s connected directly to the Internet—the gateway computer.

    But there’s a downside: If the gateway Mac is turned off or asleep, then the other machines can’t get online.

Most people use Internet Sharing to share a broadband connection like a cable modem or DSL. But there are other times when it comes in handy. If you have a cellular modem, for example, you might want to share its signal via WiFi so the kids in the backseat can get online with their iPod Touches.

The only requirement: The Internet-connected Mac must have some other kind of ...

Get Switching to the Mac: The Missing Manual, Yosemite Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.