Kinda upset at the lack of response to GBe issues

[MarkHaysHarris777]

I suspect that the reason this works is that the negotiation for GbE does not happen and by default the unit comes up  100 /full.

Just out of curiosity, with a non-modified cable, what happens if you run "sudo ethtool -s eth0 speed 1000 duplex full" ... does it give the ethernet a kick to reboot and re-negotiation as GbE/1000Mbs? I'd try myself... but as you know... it's a non-issue for me. However, I can switch between 100Mb and 1000Mb that way.

@pfeerick
hi, good question... with the unmodified cable I can use the ethtool to set speed 1000 duplex full; but, it doesn't work at all !   With the modified cable the link comes up 100 /full, which is why its working so well; if I use the ethtool to set speed 1000 duplex full it DOES go into 1000 full for about 20 seconds and then the link goes down  (this is reproducible).   If I bring the linke back up manuall without reboot [ ifconfig eth0 up ]  the link comes up 100 /full.

The temporary good news here is that while we're trying to figure out what needs to be done to the card, the 100 link comes up automatically now without intervention so that (in my case only) the GbE switch is now useful. The machines (2) that can use it do, and the one that cannot use it comes up 100 by default... so my wired GbE network just had an order of magnitude improvement !

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Using my ubuntu image and the 'bad card' connection to the GbE switch is now working !  It went from not working at all on the GbE switch to running at 95mb/s !

( we're getting closer people,  we're getting closer ! )

You're not getting closer, you just forced Fast Ethernet which is something completely different as I already tried to explain to you yesterday (read through the 'zillions of words and this time try to understand). Add 'ethtool -s eth0 speed 100 duplex full' to /etc/rc.local prior to the 'exit 0' line and you get the same without fiddling around with your cable.

The real problem is still a negotiation problem in GbE mode (which is something completely different than Fast Ethernet and that's the reason I already warned exactly you yesterday to try to understand what's happening and not using iperf now and talk about performance numbers). You used a workaround that simply works since the real problem is not even touched.

@tkaiser
Thank you tkaiser for being a student of the obvious, but unfortunately not a student who reads the history of this problem !  WE are all very aware of the point that you just posted here.  I have been recommending the "while we wait" work-around of using ethtool for setting the speed to 100/full and have been pointing people to that for weeks.

WE are also painfully aware that this is a negotiation problem... what has not been clear until recently was whether the problem was hardware or software;  it is almost certainly hardware related at the root cause.

But WE have moved forward ( from a work-around standpoint ) because now the units that do not work at 1000 GbE/full will now work at 100/full 'by default' without intervention.  While I'm working on this, my GbE switch just became useful... !   This is a big deal...  

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For everyone else:

Take a look at  www.hardwaresecrets.com/how-gigabit-ethernet-works/

All eight wires ( all four pairs ) are required for gigabit ethernet to work. So, modifying your Cat6 cable , or using a 2 piar cable is only a temporary work-around ( albeit an automatic work-around ).

marcus