Re: How are you configuring BFD timers?

[Jason Lixfeld <jason+nanog () lixfeld ca>]

A few years ago I did some testing and found that the time between the transceiver detecting LOS and the routing 
protocol (ISIS in this case) being informed that the link was down (triggering the recalculation) took longer than it 
took BFD to signal ISIS to recalculate.

> On Mar 21, 2018, at 12:35 PM, Bryan Holloway <bryan () shout net> wrote:
>
> Wouldn't any tangible problem on a dark-fiber link result in an interface shutdown, ostensibly creating the trigger 
> one would need to begin re-convergence?
>
>
> On 3/21/18 11:31 AM, Alex Lembesis wrote:
> > To speed up BGP routing convergence.  The (2x) dark fiber links from PA to FL are being used as Layer3 datacenter 
> > interconnects, where each datacenter has its own AS.  The DF is also carrying FCIP traffic, so we need failover to 
> > be as fast as possible.
> > Best regards,
> > Alex
> > -----Original Message-----
> > From: Job Snijders (External) [mailto:job () instituut net]
> > Sent: Wednesday, March 21, 2018 12:25 PM
> > To: Youssef Bengelloun-Zahr
> > Cc: Alex Lembesis; NANOG
> > Subject: Re: How are you configuring BFD timers?
> > Silly question perhaps, but why would you do BFD on dark fiber?
> > Kind regards,
> > Job
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