On Sat, Mar 26, 2016 at 04:17:44PM +0100, Martin Mares wrote: Hi,
I also see this issue on several stretch VMs. In network segments where Router Advertisements are present but the machines have a gateway set the systems are occasionally not reachable after a reboot (<1% of the cases I'd say, totally random). It looks like they already/still have an IPv6 default route configured by RA when ifupdown attempts to add the default route, which fails. Shortly after the RA route is dropped (due to accept_ra 0) and the machine is unreachable. A possible solution could be to change "add" to "replace" in https://salsa.debian.org/debian/ifupdown/blob/master/inet6.defn#L97 . Bernhard
