[ofa-general] [RFC] ipoib: multicast sender will leave the group when neighbour is cleaned

[Roland Dreier]

 > The problem:
 > A multicast sender joins the MGID as full member, but does not leave
 > (as long as the interface is up). This causes an MGID leakage in the
 > SM.

I think ipoib has used send-only joins for a while now.  But the problem
of never cleaning up these memberships stands.

Thanks for looking at this -- it would be nice to deal with this.

 > An issue we found with this solution, is that it takes a while until the
 > neighbour is cleaned, and it requires that the host will send some traffic
 > (I supposed that unless we put more entries in the routing table, out neighbour
 > will not be garbage collected).

Would it work to have a more naive approach, and just keep track of the
last time each send-only membership was used, and set up a timer that
runs, say every minute, and garbage collect send-only memberships that
are more than 2 minutes old, or something like that?

 - R.