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I thought most (if not all) gigabit Ethernet implementations auto-detect host-to-host connections and handle the crossover for you.

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They all do now, but it's still an optional element of the standard.

It was optional in 100Mbit. In gigabit, it is mandatory.

"Automatic MDI/MDI-X Conﬁguration is intended to eliminate the need for crossover cables between simi-lar devices. Implementation of an automatic MDI/MDI-X conﬁguration is optional for 1000BASE-T devices. The assignment of pin-outs for a 1000BASE-T crossover function cable is shown in Table 40-12 in 40.8."

Here's a link that does not require IEEEXplore access: http://www.scribd.com/doc/46141801/802-3ab-1999

I say, I stand corrected. I was sure I read the opposite somewhere, but I would not dream of contesting your reference.

They do. Maybe he meant 100BASE-T4.

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