On Wed, Feb 15, 2012 at 12:24:50PM -0500, Stefan Fouant wrote: > The cool thing is the Backup RE is actually listening to all the > control plane messages coming on fxp1 destined for the Master RE > and formulating it's own decisions, running its own Dijkstra, > BGP Path Selection, etc. This is a preferred approach as opposed > to simply mirroring routing state from the Primary to the Backup > is because it eliminates fate sharing where there may be a bug > on the Primary RE, we don't want to create a carbon copy of that > on the Backup.
I don't really buy that argument. Running the same code with the same algorithm against the same data usually leads to the same results. You'll get full bug redundancy - I'd expect RE crashing simultaneously. Did NSR protect from any of the recent BGP bugs? The advantage I see are less impacting failovers in case of a) hardware failures of active RE, or b) data structure corruption happening on both REs [same code => same bugs], but eventually leading to a crash of the active RE sooner than on the backup RE, or c) race conditions being triggered sufficiently differently timing-wise so only active RE crashes. Am I missing something? Best regards, Daniel -- CLUE-RIPE -- Jabber: d...@cluenet.de -- dr@IRCnet -- PGP: 0xA85C8AA0 _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
