> Say wlan0 vanishes. All the routes going out that interface are no > longer valid, but from what I understood of this patch, it will loop for > a while, then give up.
If wlan0 vanishes, this will be recognised the next time check_interfaces is run, and all neighbours visible through wlan0 will be flushed. The issue we're having is a race condition -- if wlan0 goes down and then back up before we run check_interfaces, and the IP addresses don't change, then check_interfaces will not notice the transition, and Babel will think that its routes through wlan0 are still up -- end you end up with a FIB that is not a subset of the RIB. Ouch. So it might be a good idea to run check_interfaces early when we get EAGAIN, but I'm not sure what consequences it might have -- EAGAIN can also happen when we're under load, and we'd rather not be repeatedly scanning our interfaces in that case. It would be better to get async notifications from the kernel about interfaces going down. > Not clear to me if this would happen for 4 hello intervals before the > interface is recognised as gone? No, the hellos are used to notice vanishing neighbours, not vanishing interfaces. That's a completely different mechanism. -- Juliusz _______________________________________________ Babel-users mailing list [email protected] http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/babel-users
