[c-nsp] Switch Port Question

[Aaron Riemer]

Ahh silly me Thanks for the clarification mate :)

Cheers,

Aaron.

-----Original Message-----
From: Lincoln Dale [mailto:ltd at cisco.com] 
Sent: Tuesday, 25 January 2011 11:19 AM
To: Aaron Riemer
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Switch Port Question


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.=