On Wed, May 11, 2016 at 03:48:19PM +0200, Juliusz Chroboczek wrote: > > BTW, why Babel accepts unfeasible updates of non-selected routes? It will > > not cause problems as such route cannot be selected later (due to its > > unfeasibility) but it seems strange. > > Yeah, very good question. It's counterintuitive for me too, but it turns > out to work better that way: > > 1. Having an unfeasible route available makes it possible to use it for > fallback after a single seqno increase. If the route were not in your > routing table at all, you'd need to acquire it after your selected > route disappears, which may take some time, and will require even more > time for things like link quality and hysteresis to converge. > ...
Thanks, that makes sense. But now i wonder why not to accept unfeasible updates of selected routes? (At least in a case where router ids differ and the the update is handled as retraction.) Obviously, that would case the route to be de-selected. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: [email protected]) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."
