Re: netbsd-9 ip6 kernel log messages
On Fri, Aug 30, 2019 at 05:02:40PM +, Martin Husemann wrote: > FWIW: I started seeing this messages too. > So far only twice after boot (likely when ND was done for the first time). This is on a diskless machine, so static IPv4 config, and dhcpcd for IPv6: ip6mode=autohost dhcpcd=YES dhcpcd_flags="-6" It has full IPv6 connectivity (and it works fine). Martin
Re: netbsd-9 ip6 kernel log messages
FWIW: I started seeing this messages too. So far only twice after boot (likely when ND was done for the first time). Martin
Re: netbsd-9 ip6 kernel log messages
On 2019-08-30 03:22, Robert Elz wrote: Thanks for the detailed analysis! Since you have v4 statically configured, I will guess that you're not starting dhcpcd Correct. - if that's not running, the kernel is managing v6 autoconfig for you. Your initial message said "/var/log/messages gets spammed with..." from which I have been assuming not just one message, but many. From dmesg(8): [...] [ 97324.649076] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [ 97324.649076] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [ 97326.651757] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [ 97326.651757] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [ 97330.657141] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [ 97330.657141] in6_setscope: can't set scope for not loopback interface vioif0 and loopback address ::1 [...] Assuming the time is in seconds, the messages come in pairs, in consistent distances of 2, 4 and 4 seconds. Can you deduce from the timestamps the appoximate frequency, and perhape correlate that with the frequency of RA messages from whatever v6 enabled router is on the same (bridged, I am guessing from voif0) network link? I tcpdump(8)ed ~1000 icmp6 packets, and there wasn't a single router advertisement; they were all "neighbor solicitation"s. Cheerio, hauke -- The ASCII Ribbon CampaignHauke Fath () No HTML/RTF in email Institut für Nachrichtentechnik /\ No Word docs in email TU Darmstadt Respect for open standards Ruf +49-6151-16-21344
Re: netbsd-9 ip6 kernel log messages
Date:Thu, 29 Aug 2019 11:15:47 +0200 From:Hauke Fath Message-ID: | I understand. But in terms of network configuration, this is a very | plain setup, just a static ip4 address. Which is why I am left puzzled... v6 is designed to autoconfigure, manually configuring something is not supposed to be needed, so if you're in an environment where v6 is available, that should be happening, unless you take steps to specifically prevent it. Since you have v4 statically configured, I will guess that you're not starting dhcpcd - if that's not running, the kernel is managing v6 autoconfig for you. Your initial message said "/var/log/messages gets spammed with..." from which I have been assuming not just one message, but many. Can you deduce from the timestamps the appoximate frequency, and perhape correlate that with the frequency of RA messages from whatever v6 enabled router is on the same (bridged, I am guessing from voif0) network link? That is, I would assume that what you're seeing is the kernel's attempt to handle the RA messages it is seeing, and if that seems plausible, it would seem like a good idea to dump one of those, something like tcpdump -vv -i voif0 -s1600 icmp6 which should result in something like: 08:16:50.680157 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::c0ea:b0ff:fe55:6190 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 24 hop limit 64, Flags [managed], pref low, router lifetime 30s, reachable time 0s, retrans time 0s source link-address option (1), length 8 (1): c4:6e:1f:46:e5:cc 0x: c46e 1f46 e5cc (perhaps other icmpv6 messages as well, which will not be relevant for this, so wait for a RA to fly past - the frequency of the log messages should give you an idea how long that might be - but allow for these messages not being synchronised, they are sent at an average interval but with randomness included in the actual gaps between messages). My current guess is that perhaps the RA is including loopback the loopback prefix as an "on link" prefix, and the kernel is actually attempting to use that, rather than rejecting it. kre
Re: netbsd-9 ip6 kernel log messages
On 2019-08-29 10:43, Robert Elz wrote: Date:Thu, 29 Aug 2019 09:59:01 +0200 From:Hauke Fath Message-ID: | What gives you the impression that I did? I misread your ifconfig output. Sorry. But that is what the error message you reported mean, when a loopback address is being added to a non-loopback interface, that message is logged. Something is making that happen. I understand. But in terms of network configuration, this is a very plain setup, just a static ip4 address. Which is why I am left puzzled... | ip6 isn't even configured on the machine. In terms of addresses, no, but it is enabled, as shown in your ifconfig output. Well, that is what NetBSD does out of the box. What is the system's hostname set to? And what is in either /etc/ifconfig.voif0 or ifconfig_voif0 (whichever you use) [you can drop any v4 addressees, this is a v6 issue.] # hostname oak # cat ifconfig.vioif0 netmask 255.255.255.0 # Cheerio, hauke -- The ASCII Ribbon CampaignHauke Fath () No HTML/RTF in email Institut für Nachrichtentechnik /\ No Word docs in email TU Darmstadt Respect for open standards Ruf +49-6151-16-21344
Re: netbsd-9 ip6 kernel log messages
Date:Thu, 29 Aug 2019 09:59:01 +0200 From:Hauke Fath Message-ID: | What gives you the impression that I did? I misread your ifconfig output. Sorry. But that is what the error message you reported mean, when a loopback address is being added to a non-loopback interface, that message is logged. Something is making that happen. | ip6 isn't even configured on the machine. In terms of addresses, no, but it is enabled, as shown in your ifconfig output. What is the system's hostname set to? And what is in either /etc/ifconfig.voif0 or ifconfig_voif0 (whichever you use) [you can drop any v4 addressees, this is a v6 issue.] kre
Re: netbsd-9 ip6 kernel log messages
On 2019-08-29 00:46, Robert Elz wrote: Thanks for looking at this. Date:Wed, 28 Aug 2019 17:43:04 +0200 From:Hauke Fath Message-ID: | /netbsd: [ 22431.3702756] in6_setscope: can't set scope for not loopback | interface vioif0 and loopback address ::1 ::1 should only be configureds as an address on lo0 - why are you trying to assign it to vioif0 ? What gives you the impression that I did? ip6 isn't even configured on the machine. While it has a public ip6 address, I didn't get to that yet. # fgrep ::1 /etc/* /etc/hosts:::1 localhost localhost. /etc/hosts.allow:ALL : [::1] 127. /etc/ntp.conf:restrict ::1 # is all there is. Cheerio, hauke -- The ASCII Ribbon CampaignHauke Fath () No HTML/RTF in email Institut für Nachrichtentechnik /\ No Word docs in email TU Darmstadt Respect for open standards Ruf +49-6151-16-21344
