Date: Tue, 12 Jan 2021 16:33:17 +0300 From: "Andrey V. Elsukov" <bu7cher@yandex.ru> To: Lutz Donnerhacke <lutz@donnerhacke.de>, freebsd-net@freebsd.org Subject: Re: FreeBSD does not reply to IPv6 Neighbor Solicitations Message-ID: <95be49e2-56cc-cf3f-3515-8f13f14ddbad@yandex.ru> In-Reply-To: <20210112022525.GN31099@funkthat.com> References: <mailman.93.1609761601.91504.freebsd-questions@freebsd.org> <E9644A2A-6C5F-48C9-AD2D-13BC7FB2E534@gromit.dlib.vt.edu> <20210105031528.GA91534@admin.sibptus.ru> <00a101d6e33b$96edf0c0$c4c9d240$@donnerhacke.de> <20210105104650.GA7688@admin.sibptus.ru> <00b601d6e35a$115a4a20$340ede60$@donnerhacke.de> <20210112022525.GN31099@funkthat.com>
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This is a multi-part message in MIME format. --------------120027B1794E44F3043DF14A Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 12.01.2021 05:25, John-Mark Gurney wrote: >> The device, where the capture was taken does not respond tot he NS packet. >> This might be caused by: >> a) the device has a different configured IP address, than requested >> b) the network card does not listen to the multicast group, which is >> used by the request (you see it only due to the promisc mode of the >> capture). But this is unlikely (due to the promisc mode) >> c) your system is broken > > I have some test scripts where something similar to this happens. > > I tcpdump shows the request coming into the FreeBSD box (in this case, > 13-current main-c255640-gc38e59ce1b0), addressed to the IPv6 of the > box, and FreeBSD failing to respond w/ an answer for it's own IP... > > This is inconsistent and hard to reproduce, but it does happen with > somewhat regularity. Hi, when this will happen again, it would be nice to make sure that NS packets hit the IP stack. E.g. with attached dtrace script. Also net.inet6.icmp6.nd6_debug variable should be set to see error messages from ND code. If it doesn't show expected info, this means that packets don't hit IP stack. Probably some multicast related problem. In this case it could be useful to obtain output of ifmcstat(8). -- WBR, Andrey V. Elsukov --------------120027B1794E44F3043DF14A Content-Type: text/plain; charset=UTF-8; name="nd6.d.txt" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="nd6.d.txt" IyEvdXNyL3NiaW4vZHRyYWNlIC1zCgpmYnQ6Om5kNl9uc19pbnB1dDplbnRyeQp7CglpcCA9 IChzdHJ1Y3QgaXA2X2hkciAqKWFyZ3NbMF0tPm1fZGF0YTsKCW5kID0gKHN0cnVjdCBuZF9u ZWlnaGJvcl9zb2xpY2l0ICopYXJnc1swXS0+bV9kYXRhICsgYXJnc1sxXTsKCglwcmludGYo IiVzOiBOUyBmcm9tICVzIHRvICVzLCB0YXJnZXQgJXMiLAoJICAgIHN0cmluZ29mKGFyZ3Nb MF0tPm1fcGt0aGRyLnJjdmlmLT5pZl94bmFtZSksCgkgICAgaW5ldF9udG9hNigmaXAtPmlw Nl9zcmMpLCBpbmV0X250b2E2KCZpcC0+aXA2X2RzdCksCgkgICAgaW5ldF9udG9hNigmbmQt Pm5kX25zX3RhcmdldCkpOwp9CgpmYnQ6Om5kNl9uYV9vdXRwdXRfZmliOmVudHJ5CnsKCglw cmludGYoIiVzOiBOQSB0byAlcywgdGFyZ2V0ICVzIiwKCSAgICBzdHJpbmdvZihhcmdzWzBd LT5pZl94bmFtZSksIGluZXRfbnRvYTYoYXJnc1sxXSksCgkgICAgaW5ldF9udG9hNihhcmdz WzJdKSk7Cn0K --------------120027B1794E44F3043DF14A--
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