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Comment by jccalhoun | Hacker News Reader

A few years ago, when i was a grad student at Indiana University, I was told that one of the dorms required students to use a specially wired ethernet cable as recently as 10 years ago because the building had been wired before the ethernet standard was finalized and they chose the wrong wiring order.

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couldn't they 'undo' the mistake between the wall and the switches in the basement?

A common mistake back in the early days of Ethernet was to wire them as four sequential pairs, instead of the required (1-2) (3-6) (4-5) (7-8). This worked most of the time on 10BaseT networks, but would get flakey at 100Mbit.

If they got the pairs wrong at the wall jacks, there's not much you can do without repatching the whole thing. If they realized that they could make short cables that fixed it so that the pairs were mapped properly to port pins, that's quite clever in my books!

At one of my local universities (also in the midwest US) ethernet jacks in the dorms were intentionally miswired so that only cables supplied by the university (and more specifically, their favored vendor) would work.

Of course you could always make your own cable, but this was in the 90's, when the tool for that was very expensive.

I would think so but I don't really know the ins and outs of wiring. I think about 5 or so years ago they remodeled the dorm and made it so you didn't need the custom cable.

They had a classroom in that dorm I taught in and remember near the end of the semester seeing signs telling people to remember to return their cable.

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