[openib-general] [Fwd: RE: IB mcast question]

[Hal Rosenstock]

On Tue, 2006-08-15 at 17:18, Sean Hefty wrote:
> > > App 1:
> > > Creates QP with QKey=22
> > > Joins multicast group 1 with QKey=33
> > >
> > > App 2:
> > > Creates QP with QKey=44
> > > Joins multicast group 1
> > > Sends to multicast group but with QKey=22
> >
> >I think that last send is technically an IBA spec violation.
> 
> I'll admit that this definitely seems like a hack, but I haven't found where it
> is violation.  (I'll keep looking.) 

The first occurrence that I find is the following:

p.145 13) where it states that "Further, in addition to having the same
MGID, all members of the multicast group must share the same P_Key and
Q_Key.

That is compliance per C4-3 on p. 143.

There may be others.

-- Hal

>  From 10.5.2.1, a QP doesn't need to be
> attached to a multicast group to initiate a send, so it seems like any potential
> violation is only that the QKey and MLID wouldn't match.
> 
> - Sean