[c-nsp] Basic Etherchannel Question

[Phil Mayers]

On 01/15/2011 06:12 PM, Keegan Holley wrote:

>
>     At one time the Cisco "fast convergence" SRND recommended channel
>     mode of "on" because it was a bit quicker bringing links up. We
>     followed that advice, but TBH I've been reconsidering it lately.
>
>     To an extent it depends on what *kind* of etherchannel you're
>     talking about. If it's router->router and you control the fibre
>     patching, a mis-patch is less likely.
>
>     But if it's towards an edge server, where mis-patching gets more
>     likely, LACP seems like a no-brainer.
>
>
> I'm less concerned with connecting to the wrong device than with
> diagnosing failures.  I've seen issues where a link in a hardcoded
> etherchannel stops passing traffic but is not removed from the channel
> since there is no negotiation protocol running.  Would dynamic protocols
> help here or is it not worth the risk?  Just to be clear I'm talking
> about LACP, but I assume PAGP is capable of the same.

Using LACP is probably better than not. It might not detect all faults, 
but it'll probably be better than nothing and it's hard to imagine it 
causing problems. LACP is pretty mature these days.