On Tue, Apr 20, 2021 at 10:09:47AM -0400, Jan Schaumann wrote: > Greg Troxel <[email protected]> wrote: > > > > Jan Schaumann <[email protected]> writes: > > > > > Apr 20 01:32:32 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router > > > Apr 20 01:32:34 netbsd dhcpcd[17397]: xennet0: Router Advertisement from > > > fe80::caa:49ff:feaf:1815 > > > Apr 20 01:32:35 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 > > > is unreachable > > > Apr 20 01:32:35 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router > > > Apr 20 01:32:44 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 > > > is reachable again > > > Apr 20 01:32:52 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 > > > is unreachable > > > Apr 20 01:32:52 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router > > > Apr 20 01:32:54 netbsd dhcpcd[17397]: xennet0: Router Advertisement from > > > fe80::caa:49ff:feaf:1815 > > > Apr 20 01:32:55 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 > > > is unreachable > > > Apr 20 01:32:56 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router > > > > I don't know what's wrong, but obviously you should 'tcpdump -w IPV6 > > ip6' and look at it. > > That's unfortunately not very revealing, as it merely > shows the neighbor solicitations and router advertisements:
In the cases we had before, it was always two advertisements short after each other. The first one declared the router to no longer be active and the second declared it to be alive again. I forgot which of the timer fields was the mark for that. I was wondering about adding a hackish workaround for such misconfigured routers so that the first event is not processed for a second or two and ignored if it is cancelled within that window. Joerg
