Would it be possible to use a virtual interface from within bind/named that gets mapped by some privileged facility to a hardware interface? (This is the sort of thing that VMs have to do all the time.) For example, could a brctl bridge help?
Or maybe CAP_NET_BIND_SERVICE would allow the interface to be reactivated (if it's a privileged port issue). Just brainstorming. Paul On Fri, 12 Feb 2021 18:33:21 -0500 bindus...@prograde.net wrote: > Greetings, > > I’ve been fighting a two-fold problem with named (bind 9.16.11) running on > macOS. > > 1: If an ethernet interface being listened to drops link, named immediately > stops listening to it: > > 12-Feb-2021 17:33:19.326 no longer listening on 192.168.88.220#53 > > and > > 2: when link returns I get 2 tries to reestablish listening: > > 12-Feb-2021 17:33:39.458 listening on IPv4 interface en1, 192.168.88.220#53 > 12-Feb-2021 17:33:39.463 creating IPv4 interface en1 failed; interface ignored > 12-Feb-2021 17:33:41.946 listening on IPv4 interface en1, 192.168.88.220#53 > 12-Feb-2021 17:33:41.951 creating IPv4 interface en1 failed; interface ignored > > which both fail because named is no longer running as root. > > -------------- > > Where I’m confused is that this ISC KB article: > > https://kb.isc.org/docs/aa-00420 > > seems to imply that the "no longer listening" event is due to a periodic > interface scan finding the interface "unavailable". > > That doesn’t fit my observations since it happens as soon as link is lost. If > some minutes-long periodic scan were needed to detect the interface being > down it would take, on average, half of that period to happen. It does not. > > Further, I tried what the KB article advised by adding the option: > > interface-interval 0; > > That does seem to stop the periodic scan (since my log is no longer filled > with errors) but the “no longer listening” event still occurs right when the > interface drops. > > -------------- > > Is it not possible to have named drop to a non-root user (via -u) but still > recover from (or ride through) a momentary ethernet link loss? > > Having the server stop working due to a switch I have no control over burping > is very suboptimal. > > Thanks for any ideas. > > _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
