On Fri, Oct 18 2019 12:45:54 +0300, Lauri Tirkkonen wrote: > Hi, I updated one of my OpenBSD VM's hosted on Hetzner to 6.6 using > sysupgrade. After upgrade the network stopped working. > > The following message repeats in dmesg (106 times, before I worked > around it): > > arpresolve: 172.31.1.1: route contains no arp information > > I was able to work around and get network connectivity by removing the > route and re-adding it manually: > > route del default 172.31.1.1 > route add default 172.31.1.1 > > hostname.vio0 is configured as follows > > % cat /etc/hostname.vio0 > dhcp > -soii > inet6 2a01:4f9:c010:156b::1337 > > IPv6 works normally after reboot, but v4 requires the route del/route > add workaround.
The crucial bit here seems to be '-soii'. This workaround was previously required on Hetzner for IPv6 connectivity, but since sys/netinet6/in6_ifattach.c r1.113 http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/sys/netinet6/in6_ifattach.c?only_with_tag=OPENBSD_6_6 it isn't. So to fix my VM properly I just removed '-soii'. But it's still very strange that '-soii' would break *IPv4*. So I tried to do some more digging: I booted old snapshot bsd.rd's from ftp.hostserver.de archives, started a shell in them and did: dhclient vio0 ifconfig vio0 -soii to verify whether the problem exists. The results: https://ftp.hostserver.de/pub/OpenBSD/6.5/amd64/bsd.rd OK https://ftp.hostserver.de/archive/2019-06-06-0105/amd64/bsd.rd bad Unfortunately older snapshots than that are not available any more from ftp.hostserver.de, so digging in more detail is harder. I also tried to build more recent kernels, up to the Aug 21 commit to in6_ifattach.c above, on top of a fresh 6.5 install, but could not reproduce the problem (which suggests the problem may be triggered by a userland change instead). -- Lauri Tirkkonen | lotheac @ IRCnet
