[c-nsp] Ethernet autonegotiation issue between Cat3560 and Cat2960

[Juuso Lehtinen]

Thanks to all for answers,

Cables straight-thru, and identical cables are used for the working and
suspended trunks.

I will try replacing the cable with a new one tomorrow. If that does not
help, will try disabling autonegotiation.


On Sun, Nov 22, 2009 at 6:05 PM, Nick Hilliard <nick at inex.ie> wrote:

> On 22/11/2009 12:46, Juuso Lehtinen wrote:
>
>> Any ideas what might be causing this. I wonder if I'm running into some
>> kind
>> of minimum cable length problem. Switches are sitting adjacent to each
>> other
>> in a rack and connected with very short cables (0.5m ~ 2 ft).
>>
>
> Are you sure you're using the correct cable type?  Either you should use a
> regular 568-B straight-thru cable, or else you should use a full GE
> crossover cable, which is wired like this:
>
> 1.      white/orange    ->      white/green
> 2.      orange/white    ->      green/white
> 3.      white/green     ->      white/orange
> 4.      blue/white      ->      brown/white
> 5.      white/blue      ->      white/brown
> 6.      green/white     ->      orange/white
> 7.      white/brown     ->      white/blue
> 8.      brown/white     ->      blue/white
>
> Note that for a 100M cross-over, you only cross orange with green, but for
> GE, you need to cross blue with brown too.
>
> Even if you're sure about the cabling, it's no harm to test it out with a
> decent cable tester.  Maybe there's something strange going on with the UTP
> termination plugs?
>
> Cable length is only a problem where you use co-ax, as the co-axial cable
> medium can encourage all sorts of strange effects (signal reflection, timing
> problems, etc).
>
> Nick
>
>