Can't get Giga etheet with this cable... but why?

I'm asking here after finding and reading Why is my LAN not gigabit?

Similarly, I have a CAT5e patch cable which will only connect at 100Mbps. All my other cabling is CAT6, but this one patch cable isn't. It is 30M long. From everything I read, that should be capable of gigabit, right? Swap it with a CAT6 and I get gig... no other changes.

Is it a bad cable, or is 5e really not so giga-capable as I thought? I have confirmed with a multimeter that all 8 wires are good from end-to-end and they have the same color sequence from left-to-right.

No errors. No dropped packets. Just won't negotiate at gig.

Thanks.

Edit: Almost immediately after posting, I found another 5e cable to test with although it is shorter (50ft vs 30M... about half). It successfully makes a 1Gbps link. So the question now is: Is something wrong with my 30M cable? Or is 30M just too long for Giga speed?

Recent Questions...