On Mon, 13 Apr 2020 at 00:44, Mark Tinka <[email protected]> wrote:
> What we've generally done is make sure the lowest level protocol reacts > as quickly as possible. This way, it's (quick) reaction would inform > lateral or upper-layer protocols to react accordingly. > > So we tune IS-IS to react quickly, and enable BFD just for it. +1, only ISIS (and other SPT protocols) are topoogy aware. If ISIS converges fast, and the rest of the protocol stack is correct, then everything converges fast. LFA, rLFA, PIC, edgePIC and you can locally converge once you are aware of the outage, ~immediately. That is, convergence can happen in linecard HW, as the backup path is already programmed there, the only thing it needs to know is if-down. And the rest of the network not converged yet, are protected by the node which is aware of the failure. In JNPR this is accomplished by ECMP mechanism, a backup path is added to LC HW ECMP with inferior weight, so it's not actually used. So if a linecard can for any reason remove the superior weight (int down) it can also start using the inferior weight, without understanding anything about the fault. -- ++ytti _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
