From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: IGMP Join dropping multicast packets
Date: Tue, 17 Mar 2009 08:08:23 +0100
Message-ID: <49BF4C67.9000808@cosmosbay.com>
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Cc: netdev@vger.kernel.org
To: Dave Boutcher <daveboutcher@gmail.com>
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Eric Dumazet a =E9crit :
> Dave Boutcher a =E9crit :
>> On Sat, Mar 14, 2009 at 9:37 PM, Eric Dumazet <dada1@cosmosbay.com> =
wrote:
>>> Dave Boutcher a =E9crit :
>>>> I'm running into an interesting problem with joining multiple
>>>> multicast feeds.  If you join multiple multicast feeds using
>>>> setsockopt(...,IP_ADD_MEMBERSHIP...) it causes packets on UNRELATE=
D
>>>> multicast feeds to get dropped.  We have a multicast feed on a roc=
k
>>>> solid network, and we were very surprised to see dropped packets. =
 The
>>>> cause was a different process/program being run by a different use=
r
>>>> joining a bunch of mulitcast feeds.
>>> I could not reproduce the problem on my machines (bnx2 adapter), ev=
en if changing
>>> NUMSOCK from 55 to 200 in joiner.c
>> Thanks for trying Eric.  Based on your email I did some more testing
>> and thus far I've
>> only recreated this on x86_64 arches, not on i386.  Which arch did y=
ou
>> try it on?
>=20
> I tried both, 32 and 64 bit kernels. No problems so far.
>=20
> Could you post a linux kernel .config of a non 'working' machine, and=
 dmesg output ?
>=20

Also, is using a third machine to start your joiner program is able to =
trigger
packet losses too ?