From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: IPoIB: Fix multicast packet drops before join is complete
Date: Fri, 05 Jun 2009 18:17:30 -0700 (PDT)
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From: Roland Dreier <rdreier@cisco.com>
Date: Fri, 05 Jun 2009 14:12:35 -0700

> ethernet is a different L2 -- you don't have to resolve an IP multicast
> address to an L2 address the way you do for IPoIB.
> 
> My point is just that multicast group join is the same sort of L2
> resolution as ARP is for ethernet, and so having the same sort of
> behavior makes sense.

Then the IPoIB layer should block on group join, not have this
limitless packet backlog which as I have explained is ill designed
and definitely not futureproof.