Date: Tue, 5 Jan 2021 10:15:28 +0700 From: Victor Sudakov <vas@sibptus.ru> To: Paul Mather <paul@gromit.dlib.vt.edu> Cc: freebsd-questions@freebsd.org, freebsd-net@freebsd.org Subject: Re: FreeBSD does not reply to IPv6 Neighbor Solicitations Message-ID: <20210105031528.GA91534@admin.sibptus.ru> In-Reply-To: <E9644A2A-6C5F-48C9-AD2D-13BC7FB2E534@gromit.dlib.vt.edu> References: <mailman.93.1609761601.91504.freebsd-questions@freebsd.org> <E9644A2A-6C5F-48C9-AD2D-13BC7FB2E534@gromit.dlib.vt.edu>
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--G4iJoqBmSsgzjUCe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Paul Mather wrote: > >>>> Why could it be that a FreeBSD 12.2 host does not reply to ICMPv6 > >>>> Neighbor Solicitations from the router? [dd] > >=20 > > $ ifconfig re1 > > re1: flags=3D8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu = 1500 > > options=3D8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSU= M,WOL_MAGIC,LINKSTATE> > > ether c4:12:f5:33:c9:7c > > inet 192.168.170.5/24 broadcast 192.168.170.255 > > inet6 fe80::c612:f5ff:fe33:c97c%re1/64 scopeid 0x2 > > inet6 2001:470:ecba:3::5/64 > > media: Ethernet autoselect (1000baseT <full-duplex>) > > status: active > > nd6 options=3D21<PERFORMNUD,AUTO_LINKLOCAL> >=20 >=20 > I notice your nd6 options do not include ACCEPT_RTADV. Perhaps this > is a reason why your interface is ignoring routing messages? =20 Well, Neighbor Solicitations (ICMPv6 type 135) and Neighbor Advertisements (ICMPv6 type 136) are not exactly routing messages, they are the equivalent of the ARP protocol in IPv6, and AFAIK should work between any two IPv6 nodes to map L3 addresses to L2 addresses, even if there are no routers on the segment. Correct me if I'm wrong. You may be right but then it is certainly a bug. Unfortunately I cannot reproduce the problem with any reliability, this thing works more often than not. > My interface ifconfig shows "nd6 > options=3D23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>" >=20 > I also use a statically-defined[*] IPv6 address, but include "accept_rtad= v" in the interface definition in /etc/rc.conf. Furthermore, I also set rt= sold_enable=3D"YES" to send router solicitation messages on the interface. This would add one or two autoconfigured global IPv6 addresses to your interface. There is no harm in that, I agree, but it's important to understand if this is a bug and can be reproduced and reported. >=20 > [*] As well as a static IPv6 address I also enable SLAAC to get autoconfi= gured and privacy addresses on the interface. >=20 I see your point, this makes sense, but I would like to try and isolate the problem. --=20 Victor Sudakov, VAS4-RIPE, VAS47-RIPN 2:5005/49@fidonet http://vas.tomsk.ru/ --G4iJoqBmSsgzjUCe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJf89nQAAoJEA2k8lmbXsY0MTIH/2ACBGPPGbBx5Dq2wlx1Bm/c dfo6Q5wWLgpEACDQXaItuF83KQOJgfcK3kUQe2saQzgqj/AbF0WGfuCSDLGOHbjz llssRPz6WKwmLTw1a1UC+Idr3V4dqHxMTSE/tYVVPm0Cm4naf1SyYWlwhpyM1zxf J41o8aUCVoqmagXUBodBfYyrX87C7kbButDR9fheYBBPQmEld+NHfdQZ2RoxPbV6 uMPdvUm/1xUhsztcjiykHsHEc7ASkZBOc3sI4k389KEKdb2Itm24XFwA6f2LxLys 6uWKvmURxx7iQtxa4PI56hB6CdgCRTDYJdi4u1OwNyv+F+yV9Te9kJt+pNXrOIU= =sa6T -----END PGP SIGNATURE----- --G4iJoqBmSsgzjUCe--
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