CPMH Tips: December 20, 1999

If you’ve got more than one Mac around the house, the fastest and most straightforward way to exchange files or share a cable modem is to set up an Ethernet network. For my SBAN (Spare Bedroom-Area Network), I have an iMac DV, a PowerComupting PowerCenter Pro Mac clone and a cable modem for the Time-Warner Roadrunner service.

With the right supplies, the task becomes a ten-minute job of plugging in RJ-45 connectors, which look like oversized phone jacks. First, though, you need to be sure that your Macs are Ethernet-ready. Most newer Macs, including iMacs and most clones, have built-in Ethernet. In my case, I was set. On the other hand, if your Macs don’t have Ethernet, you need to get an Ethernet network interface card. Check the Networking section (CPMH Chapter 3) for companies that manufacture Mac-compatible cards for PCI- or NuBus-based Macs, and follow the manufacturer’s instructions for installing the card.

Next, you’ll need to buy the appropriate network supplies. For a basic two-computer network, you’ll need an Ethernet hub and two Ethernet cables. If you’re connecting a cable modem, you probably already have a third Ethernet cable between the modem and your computer, supplied by the cable company. You should be able to find a small Ethernet hub with four or five ports for around $25. Two cables will run you less than $10 each. Total cost to you is around $50.

A technical note on buying Ethernet hubs. There are two speeds: 10-BaseT, which moves data at 10 million bits per second, and 100-BaseT, which moves data at 100 million bits per second. For almost any home network, a 10-BaseT network will suffice, so make sure you get a 10-BaseT Ethernet hub. If you look at 100-BaseT hubs, (a) the price goes up significantly, and (b) you’ll have to make sure your Macs support 100-BaseT Ethernet or that you get an autosensing 10/100-BaseT hub. Unless you want to delve into these issues, stick with the 10-BaseT Ethernet hub.

Finally, once you have your supplies, you have to plug everything together.

1. Start with the hub. It probably has a power supply, so you’ll need to plug that in. Now, turn on the hub if it has a switch. (It may be always-on.) Make sure its power LED comes on. Also, identify the port on your hub designed to be connected to another hub. This may be called an uplink port or a cascade port. Refer to your manual.
2. Connect one Ethernet cable from the first Mac’s Ethernet port to any of the ports on the hub, except the uplink port.
3. Connect the second Ethernet cable from the second Mac’s Ethernet port to any of the ports on the hub, except the uplink port.
4. If you have a cable modem, connect the third Ethernet cable from the cable modem to the uplink port on the Ethernet hub.

Network Settings

If you have a cable modem, you shouldn’t even have to change any settings for one of your Macs to communicate through the modem. However, to have both Macs simultaneously connected to the modem, you will have to contact your cable provider and let them know that you have two Macs connecting through your modem. For me, the additional charge of $5 per month was a more cost-effective option than trying to share the modem. For a network of more than two Macs, you may want to investigate software such as SurfDoubler from Vicomsoft.

If you go on-line to the Internet through your modem and a dial-up connection, you can still share files over the Ethernet. Open the AppleTalk control panel on each Mac and make sure that it is set to Connect via: Ethernet. Next, open the File Sharing control panel and Start file sharing, if it’s not already on. Once this is done, you should be able to open the Chooser on one Mac, click on the AppleShare icon, and see the other Mac. The AppleTalk settings should not interfere with the Internet (TCP/IP) settings for your ISP.

For More Information

For more complicated configurations, troubleshooting tips, and other networking tricks, you can visit the Three Macs or MacWindows Web sites.

A more complicated extension to this problem is sharing a printer between two Ethernet-connected Macs. That will be the subject of several forthcoming CPMH Web Tips.