Problems connectivity GE on Foundry BigIron to Cisco 2950T

Jeff Rosowski rosowskij at
Mon Feb 6 17:50:00 UTC 2006

> According to "Ethernet, The Definitive Guide", that feature is an
> optional part of the spec.
> One thing I've heard people encounter is that if they use a cross-over
> cable, which probably really implies a 100BASE-TX cross-over, then the
> ports only go to 100Mbps. A Gig-E rated straight through, in conjunction
> with the automatic crossover feature, was necessary to get to GigE.

A lot of cross over cables only cross pairs 1-2 with 3-6, leaving 4-5, and 
7-8 as straight through.  Gig-E uses all four pair.

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