[c-nsp] Switch Port Question

[Lincoln Dale]

On 25/01/2011, at 2:13 PM, Aaron Riemer wrote:

> Hi Lincoln,
> 
>> yes,
>> swltch 2 would consider the interface to be operationally down (loss of
> light).
>> switch 1 is still receiving light. 
> 
> If the interface is considered to be operationally down why does it still
> transmit light out its TX path?? This is what is confusing me.

because if it did not you'd have a chicken/egg situation.  if switch #2 did not send light to switch #1 because it was not receiving it, you'd never get link-up in the first place.

this is what protocols like UDLD, BFD, STP, routing protocols et al all confirm there is bidirectional connectivity.


cheers,

lincoln.