[ltp] 100mbit only when docked?

Richard Neill linux-thinkpad@linux-thinkpad.org
Wed, 08 Apr 2015 18:25:45 +0100

On 07/04/15 10:54, Christoph Schmees wrote:
> Am 30.03.2015 um 01:38 schrieb Richard Neill:
> ...
>> You can check the hardware and cables of most ethernet devices by using
>> TDR (time-domain reflectrometry).
> to my knowledge TDR is pure hardware, and not even computer but
> high sophisticated electronics. Nothing w/ BIOS or Linux.

Hi Christoph,

I recall using this in a R60 some time ago. The Network card has the 
hardware built in (I think it was part of the Broadcom PHY), and it was 
a neat (though quite deeply hidden) option within the BIOS diagnostics 
to test cables - and indeed, I used it to find the break in a very long 
cat 5 cable (it located it, correctly, within 50cm in a 65m cable run). 
The R60 also had support for doing this within the network driver's 
advanced tests in Windows. Sadly, Linux didn't support it.