[c-nsp] disabling GigE negotiation on NX-OS

[Phil Mayers]

On 04/16/2011 12:48 AM, Keegan Holley wrote:
> I don't think fiber negotiates.  It isn't usually capable of anything
> but gig-full.  Are you sure the carrier is using 1g fiber.  Carriers

Sigh.

The IEEE really did drop the ball on gig autoneg.

"Maybe someone will make a fibre hub!"

Fibre gigE can either do autoneg or not. Disabling it is usually a 
mistake (but gert is clueful enough to know what he's doing). It's 
enabled by default on every platform I've ever dealt with.

Copper gigE always autonegs. You might fix the capabilities, but it 
still always autonegs.

> are always provisioning 100m smf interfaces for low-cap connections

Does 100m mean "100 metre" or "100Fx" here?

Because 100Fx does *NOT* autoneg, which leads to all kinds of tedious 
nonsense (e.g. duplex mismatches) - this is why disabling autoneg == bad.

But we're talking about gigE. And gigE fibre can (and usually should be) 
autoneg.