Lawrence Stewart <lstew...@freebsd.org> wrote in <56d1a947-a0a1-0297-7151-4e36ab53c...@freebsd.org>:
ls> On 29/03/2017 21:49, Rui Paulo wrote: ls> > On Wed, 2017-03-29 at 21:46 -0500, Lawrence Stewart wrote: ls> >> [resurrecting an old thread] ls> >> ls> >> On 19/06/2014 23:08, Hiroki Sato wrote: ls> >>> Larry Rosenman <l...@lerctr.org> wrote ls> >>> in <20140619140801.ga65...@thebighonker.lerctr.org>: ls> >>> ls> >>> le> > le> Ideas? (I may be an idiot, so any criticism welcomed). ls> >>> le> > le> ls> >>> le> > le> if you need the 1841's config, I can supply that as ls> >>> well. It's using a Hurricane ls> >>> le> > le> electric Tunnel. ls> >>> le> > ls> >>> le> > How frequent were the log message added into ls> >>> /var/log/messages? And ls> >>> le> > when did it start to happen after boot. Just after lagg0 is ls> >>> le> > configured? ls> >>> le> > ls> >>> le> > -- Hiroki ls> >>> le> Looks like: ls> >>> le> ls> >>> le> Jun 12 07:00:01 thebighonker kernel: in6_ifadd: ls> >>> 2001:470:1f0f:3ad:223:7dff:fe9e:6e8a is already configured ls> >>> ls> >>> Thank you. Three more questions: ls> >>> ls> >>> 1. output of "ifconfig lagg0", "ifconfig bce0", and "ifconfig ls> >>> bce1". ls> >>> ls> >>> 2. output of "netstat -s -i". ls> >>> ls> >>> 3. output of "ndp -p". ls> >>> ls> >>> The cause of the message is that the automatically-configured ls> >>> address ls> >>> is not recognized as "configured" one and FreeBSD IPv6 stack is ls> >>> trying to add it every time a Router Advertisement message is ls> >>> received. I am still not sure why it happened, but the above ls> >>> three ls> >>> would help for further investigation. ls> >> ls> >> I've recently set up a VPS with v6 and am seeing the same "in6_ifadd: ls> >> <v6_addr> is already configured" messages in response to periodically ls> >> received router advertisements every 5-10 mins. The host is a KVM- ls> >> based ls> >> virtual machine with vtnet-based NIC. v6 is fully functional with the ls> >> statically assigned v6 address, but the spam in /var/log/messages is ls> >> annoying. ls> >> ls> >> ls> >> FreeBSD revision: ls> >> FreeBSD lauren 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r315059: Sun ls> >> Mar ls> >> 12 20:44:50 AEDT 2017 ls> >> root@builder-head-amd64:/usr/obj/lauren/usr/src/sys/GENERIC- ls> >> NODEBUG amd64 ls> >> ls> >> ls> >> Relevant bits from /etc/rc.conf: ls> >> rtsold_enable="YES" ls> >> ipv6_activate_all_interfaces="YES" ls> >> rtsold_flags="-aF" ls> >> ifconfig_vtnet0_ipv6="inet6 <v6_addr> prefixlen 64" ls> >> ls> >> ls> >> Interface: ls> >> vtnet0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 ls> >> mtu 1500 ls> >> ls> >> options=6c07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_H ls> >> WCSUM,TSO4,TSO6,LRO,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6> ls> >> ether <mac> ls> >> inet <v4_addr> netmask 0xfffffe00 broadcast <v4_bcast> ls> >> inet6 <v6_linklocal>%vtnet0 prefixlen 64 scopeid 0x1 ls> >> inet6 <v6_addr> prefixlen 64 ls> >> nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL> ls> >> media: Ethernet 10Gbase-T <full-duplex> ls> >> status: active ls> >> ls> >> ls> >> I would have thought rtsold should be able to play nice with ls> >> statically ls> >> assigned v6 addresses... any ideas? ls> > ls> > Hmm, why would it? If you setup an IPv6 address and then there's a ls> > router solicitation advertising the same address, the log message makes ls> > sense. ls> > ls> > I don't think you should run rtsold if you have a static IPv6 address. ls> ls> How would the host learn about router(s) on the network and other ls> addresses it might want? (In my particular environment, I'm pretty sure ls> they don't change so could be statically configured, but interested in ls> understanding if (and why) these are mutually exclusive modes of operation). As Rui already pointed out, I guess you manually configured exactly the same address as the auto-configured EUI-64 address such as 2001:db8::211:85ff:fefe:d6db/64 where the upper 64 bits are equal to your IPv6 global prefix and the lower 64 bits are the same as ones in <v6_linklocal>. I do not think this manual configuration is required here. Only ifconfig_vtnet0_ipv6="inet6 accept_rtadv" line instead of the four lines in your rc.conf should work. Because most of RA options are handled in the kernel, just enabling "accept_rtadv" in $ifconfig_IF_ipv6 is sufficient. Enabling rtsold is required only when 1) an IPv6 router on your subnet is sending DNS information in RAs and you want to receive it to configure /etc/resolv.conf automatically or 2) an IPv6 router on your subnet requires DHCPv6 to IPv6 host nodes on the subnet. In both cases, some userland program has to handle the RA options. The rtsold daemon is exactly for this purpose. The other information in RAs including default routers, prefixes, MTUs, and etc. is directly handled in the kernel. Configuring a static address and enabling accept_rtadv/rtsold are not mutually exclusive. The problem is that you are using the auto-configured address manually. If you need it for some reason, you can add "autoconf" flag to the rc.conf line like this: ifconfig_vtnet0_ipv6="inet6 <v6_addr> prefixlen 64 autoconf accept_rtadv" This per-address flag means whether the address is auto-configured or not. Although normally this is set only by the kernel, you can set it by using ifconfig. If the address has this flag, the kernel thinks it has been configured by RAs and does not emit the warning messages. -- Hiroki
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