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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Ben Greear <greearb@candelatech.com>
Cc: netdev <netdev@vger.kernel.org>
Subject: Re: IPv4 multicast and mac-vlans acting weird on 3.0.4+
Date: Wed, 05 Oct 2011 21:54:09 +0200	[thread overview]
Message-ID: <1317844449.3457.3.camel@edumazet-laptop> (raw)
In-Reply-To: <4E8C89EE.3090600@candelatech.com>

Le mercredi 05 octobre 2011 à 09:46 -0700, Ben Greear a écrit :
> This is on a hacked 3.0.4 kernel...
> 
> I am seeing an issue where an IPv4 mcast receiver will not receive
> a 1473 or larger byte mcast message, but will receive a 1472.  The difference
> being that 1473 ends up being two packets on the wire.  It works on
> 802.1Q VLANs, VETH interfaces and real Ethernet.  It does not work
> on a mac-vlan hanging off the VETH.
> 
> I see packets received on the macvlan in tshark, and they appear correct.  No
> obvious errors in the macvlan port stats or netstat -s,
> and the 'ss' tool doesn't appear to support UDP sockets at all.
> 
> So, I'm about to go digging into the code, but if anyone has any
> suggestions for places to look, please let me know!
> 

Well, problem is defragmentation and macvlan cooperation.

Multicast messages are broadcasted on all macvlan ports.

But IP defrag will probably deliver a single final frame.

We probably need to handle defrag in macvlan before broadcasting to all
ports.

  reply	other threads:[~2011-10-05 19:54 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-05 16:46 IPv4 multicast and mac-vlans acting weird on 3.0.4+ Ben Greear
2011-10-05 19:54 ` Eric Dumazet [this message]
2011-10-05 20:09   ` Ben Greear
2011-10-05 20:17     ` Eric Dumazet
2011-10-05 20:19       ` Ben Greear
2011-10-05 20:31         ` Eric Dumazet
2011-10-05 20:56           ` Ben Greear
2011-10-05 21:36             ` Eric Dumazet
2011-10-05 21:52               ` Ben Greear
2011-10-05 22:35                 ` Ben Greear
2011-10-06 20:28                   ` [PATCH net-next] macvlan: handle fragmented multicast frames Eric Dumazet
2011-10-07 16:44                     ` Ben Greear
2011-10-10 16:27                     ` Ben Greear
2011-10-10 16:41                       ` Eric Dumazet
2011-10-10 16:53                         ` Ben Greear
2011-10-19  3:22                     ` David Miller
2011-10-06 20:42               ` IPv4 multicast and mac-vlans acting weird on 3.0.4+ Eric Dumazet

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