2012/1/26 Pavel Lunin <[email protected]>: > > >> >> why would FRR LSP's take a route different than what the IGP would >> converge to. > > > Because FRR uses a path from a different entry (PLP) to probably a different > exit (say, next-next-hop). When normal LSP (either SPF or CSPF calculated) > is a path from head-end to tail-end. Whether this happens often or rare, the > need to care how your detours are calculated is itself a big enough > headache.
That's not how FRR works at least for RSVP. It pretty much just re-runs cspf with something removed. So it's the same route your IGP would choose if said "thing" went dark. I don't have many obscure paths where I wouldn't want traffic to go so I can't really comment on your earlier idea. That being said I've never seen FRR choose a path worse than the path the IGP would choose. It's just preselects that path and pre-signals it. I'm sure there are failure scenarios though. > >> > What the VRF-based Internet users will definitely notice is (looks like >> > RAS >> > is tired of telling this story) is ICMP tunneling and consequent hard to >> > interpret delay values. People are very suspicious to the numbers. This >> > is >> > almost impossible to explain, that the numbers, traceroute shows, have >> > nothing to do with their kitty-photos-not-loading problem. >> >> Hey kitty photos are serious business especially if you are facebook >> stalking the aforementioned kitty. > > > Absolutely. This is why in case of issues you should not waste time for > explaining why your core router is 200ms away from the previous hop. > _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
