On 3/1/06, Sean Hefty <[EMAIL PROTECTED]> wrote: > Can someone explain when ipoib creates a multicast group?
Here's how the Linux IPoIB handles multicast: For the broadcast group, it depends on the SM having pre-created the broadcast group. It only does a join (i.e. component mask doesn't provide all the settings to create the group) for the broadcast group. Once in the broadcast group, it uses it as a template for all other groups, which allows it to issue a join with all paramters necessary to create the group if it doesn't exist already. I believe the only field that changes is the MGID. Since all IPoIB instances in the fabric use the same broadcast group, their settings for all MC groups are consistent, no matter which instance creates particular groups. In Windows, only the broadcast group join is different. In this case, the code handles the case where the broadcast group is not pre-created, and the first instance to start will create it. In that case, it picks some values for the broadcast group, mostly hardcoded except for the qkey which it generates dynamically. Once in the broadcast group, it uses it as a template for all other MC groups. - Fab _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
