On Fri, 2007-02-16 at 12:00, Roland Dreier wrote: > > We have a customer issue regarding IPv6oIB. In the subnet, there are > > limited number of MCGs supported. So when there are multiple IPv6 addresses > > are assigned to one interface, each IPv6 address will have one unique > > solicited-node address (depends on their groupID). Then in a large subnet, > > we will have tons of MCGs. If IPv6 solicited node addresses exceed the > > number of MDGs in this subnet, then IPv6 neighbour discovery will be > > broken, this won't happen in Ethernet since sendonly doesn't require sender > > to be joined any MCG. > > > I have done an initial patch to addresss MCG overflow problem and redirect > > the solicited-node address to all hosts node address, thus IPv6 neighbour > > discovery will work no matter how many IPv6 addresses in this subnet. This > > patch is only triggered with IPv6 enabled and MGC overflows, so there is > > almost no performance penalty. > > I really don't like this approach, since it can break things in very > subtle ways (eg suppose one node fails to join its solicited node > group, but then a later node wants to talk to it and succeeds in > joining the solicited node group as a send-only member -- since the > first node is not a member then it will never see the ND messages). > > I much prefer to fix the SM not to impose too-low limits on the number > of MCGs. Supporting O(# nodes) MCGs is really not a very onerous > requirement on the SM.
Is this a MFT size issue or SM issue or both ? -- Hal > - R. > > _______________________________________________ > openib-general mailing list > openib-general@openib.org > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general > _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general