[j-nsp] Segment Routing Real World Deployment (was: VPC mc-lag)

[Mark Tinka]

On 10/Jul/18 23:33, adamv0025 at netconsultings.com wrote:

> Now a robust transport network with appropriate redundancy and failover mechanisms is responsibility of each operator.
> One can use IGP tuning or take the new path computation out of the equation completely with FRR options: LDP + FRR based on LFA or even rLFA (with targeted LDP sessions all over the place) or SR with ti-LFA or RSVP-TE FRR. With FRR there's really no need to tune IGP for fast SPF path computation -but there might still be need to tune it for fast LSA/LSP propagation (think BGP-PIC "core"). 
> With FRR it then all boils down to how fast can link failures be detected -loss of light will always be the fastest method, but the good practice is to use some sort of keepalives as well (BFD/CFM/IGP-keepalives). 
> Then the faster the link down and up detection the faster the link can flap -that's where one should use dampening features (IP event dampening, bfd damping or hold-down timers -for getting interface up ) to protect your IGP (or BGP dampening for nexus users -since nexus platform doesn't have any other dampening (exception is/was 3548)). 

Agreed.

What we do is IS-IS + BFD (for IS-IS only) + (r)LFA.

Mark.