Date: Sat, 11 Jul 2009 11:27:53 +0200 From: iprebeg@freebsd.org To: Bruce Simpson <bms@incunabulum.net> Cc: freebsd-net@freebsd.org Subject: Re: em driver doesn't set multicast ethernet address Message-ID: <20090711092753.GA9630@valeria.zesoi.fer.hr> In-Reply-To: <4A5849E5.90909@incunabulum.net> References: <20090711073647.GA1824@valeria.zesoi.fer.hr> <4A5849E5.90909@incunabulum.net>
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[-- Attachment #1 --] On Sat, Jul 11, 2009 at 09:14:29AM +0100, Bruce Simpson wrote: > iprebeg@freebsd.org wrote: >> While testing -CURRENT in VMWare environment, I discovered that em >> driver doesn't properly set destination address in Ethernet header. In >> the other words, when I start listening multicast session with mcastread >> (mcast-tools), kernel triggers IGMPv3 packet. Its destionation IP is >> 224.0.0.22, but its destionation Ethernet address doesn't look like >> 01:00:5e:... Other machines that I run in same environment (like >> FreeBSD-7) behave in good manner. >> > > It seems that the introduction of IGMPv3 may have exposed some > driver/hardware issues, where certain network interfaces are not able to > transmit on groups which haven't been joined for receive. This is a bug, > and would likely break production use of IPv6, which makes heavier use of > link-scope groups than IPv4 does. > > Can you provide the following information please, so that someone can > better help you: > 1) the date of the -CURRENT code you are using; > 2) tcpdump or wireshark capture output, containing the actual output > generated by em(4). 1) Problem emerged after I upgraded to BETA1 and stayed there after I upgraded to p4 version dated 10th of July. Before that I used few months old snapshot (can't exactly tell the date). 2) dump file generated by wireshark is attached > > Does this issue occur if you use the 'mtest' tool to join 224.0.0.22 inside > the guest? The kernel will *not* listen to 224.0.0.22, unless you're > running a multicast routing daemon -- as it doesn't have to; that > link-scope group is for reports only. There is no difference, ethernet destination is still usual unicast address. > > This issue doesn't appear with IGMPv2, because it only ever transmits its > reports on the group thus joined. This has the disadvantage that multicast > routers have to have functioning promiscuous multicast receive, just to > proxy or forward traffic. > > Can you force the use of IGMPv2 using the sysctls as defined in the igmp(4) > man page as a workaround? Well, now, something really interesting happened. I changed default IGMP version via sysctl # sysctl net.inet.igmp.default_version=2 but, then I tested it with mtest and generated packets were still IGMPv3 Membership reports, but first two of them had proper mcast ethernet address. They generated sent by mtest. > > thanks, > BMS > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" [-- Attachment #2 --] ò VJ < < !)UL ) F ,@ R " VJG < < !)UL ) F ,@ Q " qVJ < < !)UL ) F (@ Q " rVJG < < !)UL ) F (@ P " ڏVJMD . . ^ )j~ F Q ۏVJx . . ^ )j~ F R VJ . . ^ )j~ F S VJ7 . . ^ )j~ F VJ^ . . ^ )j~ F VJG2 . . ^ )j~ F VJB . . ^ )j~ F VJTf . . ^ )j~ F "VJx . . ^ )j~ F "VJud . . ^ )j~ F "VJ. . . ^ )j~ F #VJ . . ^ )j~ F &VJ@ . . ^ )j~ F y &VJ, . . ^ )j~ F 'VJ} . . ^ )j~ F e 'VJL . . ^ )j~ F Z (VJC . . ^ )j~ F [ (VJ3 . . ^ )j~ F I )VJˢ . . ^ )j~ F 3 )VJR . . ^ )j~ F 4 )VJy . . ^ )j~ F - qVJ . . ^ )j~ F / uVJ& . . ^ )j~ F 0 zVJc . . ^ )j~ F 1 ~VJz * * )j~ )j~ ~VJ < < )j~ ) ) )j~ VJ < < ) ) VJ, * * ) )j~ )j~ ) VJ < < ) ) VJ * * )j~ )j~ VJY < < !)UL ) F ,@ " VJf < < !)UL ) F ,@ " VJ < < !)UL ) F ( @ " VJ9 < < !)UL ) F ( @ " VJ . . ^ )j~ F ` VJ. . . ^ )j~ F a KVJR . . ^ )j~ F VJ$ < < ) ) VJ% * * ) )j~ )j~ ) ϸVJ% < < !)UL ) F , @ ; " иVJJ < < !)UL ) F , @ : " VJ < < !)UL ) F ( @ < " VJMC < < !)UL ) F ( @ 9 " VJ. < < !)UL ) F ( @ " VJL < < !)UL ) F ( @ " VJЭ < < !)UL ) F ( @ " VJd < < !)UL ) F ( @ " BVJ4 > > ^ ) F 0 @ " BVJP > > ^ ) F 0 @ " ^VJ$ < < ^ ) F ( R@ إ " `VJq < < ^ ) F ( S@ ؤ " VJ( < < ^ ) F ( W@ ؠ " VJ < < ^ ) F ( Y@ ؞ " VJ < < ^ ) F ( @ x " VJ < < ^ ) F ( @ w " VJ < < !)UL ) F ( @ m " VJ< < < !)UL ) F ( @ g " VJ < < !)UL ) F , @ > " VJ0 < < !)UL ) F , @ = " VJ< < < !)UL ) F ( @ = " VJՍ < < !)UL ) F ( @ < " VJ < < !)UL ) F ( @ " VJ' < < !)UL ) F ( @ " VJ < < !)UL ) F ( @ " VJ < < !)UL ) F ( @ " VJ>: < < ) ) VJ; * * ) )j~ )j~ ) VJ' < < ) ) VJ * * ) )j~ )j~ ) VJl < < ) ) VJ * * ) )j~ )j~ ) VJwX < < ) ) VJY * * ) )j~ )j~ ) VJG < < ) ) VJa * * ) )j~ )j~ ) VJB4 < < ) ) VJ{5 * * ) )j~ )j~ ) VJ < < ) ) VJ * * ) )j~ )j~ ) VJP < < ) ) VJ! * * ) )j~ )j~ ) VJ8 < < ) ) VJ9 * * ) )j~ )j~ ) VJ7 < < ) ) VJ8 * * ) )j~ )j~ ) VJ < < !)UL ) F ,BC@ " VJ < < !)UL ) F ,BD@ " VJ < < !)UL ) F (BH@ " VJ < < !)UL ) F (BI@ " VJUN < < !)UL ) F (B@ ) " VJ! < < !)UL ) F (B@ ( "
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