[openib-general] some IB multicast sendonly thoughts

[Or Gerlitz]

> 15.2.5.17.1 GROUP MEMBERSHIP

> An endport must specify the type of multicast subscription or deletion that
> it wants. The MCMemberRecord:JoinState component indicates the
> membership qualities a port wishes to add (in joining or creating a group)
> or remove (in leaving a group). The meanings of the MCMember-
> Record:JoinState bits are:

> • FullMember: Group messages are routed both to and from the port.
> The port is considered a member for purposes of group creation and
> deletion, i.e.: if no member ports with FullMember=1 remain, the
> group may be deleted; otherwise it may not.

> • NonMember: Group messages are routed both to and from the port.
> The port is not considered a member for purposes of group creation/
> deletion.

> • SendOnlyNonMember: Group messages are only routed from the
> port; none are routed to the port. The port is not considered a member
> for purposes of group creation/deletion.

....

> MCMemberRecord:JoinState.FullMember bit must be set to 1 in the SubnAdmSet()
> request that creates a multicast group.

...

OK, assuming my setup consists of:

+1 IB node doing only multicast TX on a group

+2 an IB/Ethernet gateway

3+ Eth node doing only multicast RX on the equiv mac (forget manytoone)

The gateway design is to register for SA MGID IN/OUT traps and when it 
gets MGID IN it joins the the mgroup as ***NonMember** etc

Now, since the TX node joins as SendOnlyNonMember the SA would never 
create this group --> the TX node would never get MLID etc to create AH, 
etc etc

---> this setup is broken.

any thoughts and/or ideas would be welcome

Or.