6ft works normally. 10 footers almost never work. It connects and negotiates at gigabit speeds, but when you try to transfer a few GB of data, the transfer stalls, stutters, or fails. Of the 10 cables I bought, I have 2 reliable 6 foot cables and a 10 foot cable that works. They work just enough to make you wonder what else is wrong. No wonder. Should have known better. The Cat6 specification requires a center separator between twisted pairs and must be at least 26 AWG. This is the wrong size and there is no separator. I cut open one of the broken wires to see it.