Networking Macs : LUSENET : ATPM Macintosh Help : One Thread

I am trying to network my new Imac DV with my old 7100 which is running system 7.5.3. I have all the cables in place but I am not going through a switch. Is it possible to do this and if so how? Any help would be much appreciated.

-- Toby Shingleton (, January 18, 2001


Hi there,

If you are not going through a hub or a switch you must use what is known as a "crossover" Ethernet cable.

When connecting two Macintosh comptuers together directly via Ethernet, you use a different cable than when plugging a series of machines into a hub or switch. The reason is that the Ethernet jack on a Macintosh (or any other personal computer) is different than the port on a Hub or Switch. The difference lies in a pair of pins, which are reversed on the Hub/Switch. In fact, some hubs and switches have a port labelled "uplink". Often this port may be toggled between a numbered port and an uplink port (the hub would say on it "5/Uplink" for example and have a switch next to it). All that switch does is reverse the pins.

When connecting two Macs together, the pins need to be reversed in the cable since the ports on both machines are identical and neither port reverses the pins. A cable with reversed pins is known as a crossover cable. You can buy them most anywhere (mail order, etc.) or you can crimp your own from standard Category 5 cable. Just look online for a crimping diagram and it will tell you which pins to reverse.

Once you've got the proper cable you can switch on Personal File Sharing and connect the machines using AppleTalk. If you need help with that part, just email me and I'll be happy to walk you through it.

Hope this helps!

--Evan Trent Technical Wizard

-- Evan Trent (, January 18, 2001.

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