[openib-general] IPoIB Loading and Starting

[Hal Rosenstock]

On Wed, 2004-09-29 at 12:48, Michael Krause wrote:
> Based on IETF discussions, our intent was:
> 
> - For each partition that is enabled to support IP communication, the
> IP over IB implementation should join (create if the first) the
> associated "all nodes" multicast group.  This is analogous to Ethernet
> VLAN usage model where if allowed to communicate, one does; hence, it
> isn't a decision.

There is the "limited" broadcast group from which the parameters would
be derived for joining the "all nodes" multicast group (224.0.0.1).

> - When an endnode is enabled in the IB subnet and the IP over IB
> driver is configured, it can examine the configured P_Key and
> communicate with the SM/SA to determine what multicast groups are
> available.  Based on this information, the endnode can request to join
> a multicast group thus enabling IP over IB to issue ARP / ND
> messages.  

I don't understand the last sentence of this. For a partition that an
IPoIB interface is on (which is one of the IB port's partitions), all
the relevant multicast groups can be obtained from the SA but what does
this have to do with enabling "ARP/ND". Doesn't the broadcast group
creation/join take care of ARP ?

> - An endnode would then need to set up an event notification to
> understand when partitions were updated - add or deleted - for its
> local ports.  

Unfortunately, there is no local partition table changed event defined
in IBA.

> The endnode would also need to know whether it is the last member of
> the multicast group as well.

Not sure why this is needed by the endnode. I presume you are referring
to the last full member. The group is deleted when the last full member
leaves the group.

-- Hal