[openib-general] Multicast Group Routing Question

[Hal Rosenstock]

On Wed, 2006-12-06 at 16:06, Sean Hubbell wrote:
> Hal Rosenstock wrote:
> > On Wed, 2006-12-06 at 13:48, Sean Hubbell wrote:
> >   
> >> Hal Rosenstock wrote:
> >>     
> >>> Hi Sean,
> >>>
> >>> On Wed, 2006-12-06 at 12:52, Sean Hubbell wrote:
> >>>   
> >>>       
> >>>> Hello,
> >>>>
> >>>>   I was testing our code and noticed that when I send data using 
> >>>> multicast over our ib0 interface, all of the infiniband switches route 
> >>>> the data to each switch and each node instead of a node that has an 
> >>>> application listening to the interface like Ethernet. Is this by design?
> >>>>     
> >>>>         
> >>> It depends on what multicast group is being used and which end nodes
> >>> have registered for that group as to where the data is routed.
> >>>
> >>> -- Hal
> >>>   
> >>>       
> >> Hey Hal,
> >>
> >>   The multicast group I am sending data to is 224.10.10.x (not 
> >> 224.0.0.x) and I have no clients / nodes listening but the data is still 
> >> being sent.
> >>     
> >
> > Yes, if there is only a sender, the data should not be routed anywhere.
> >
> >   
> >>  I am using wwtop from warewulf to view the network load for 
> >> each node.
> >>     
> >
> > I'm not familiar with those tools.
> >
> >   
> >>  Does this make sense?
> >>     
> >
> > Nope. To state the obvious, something is not as it seems...
> >
> > Can you state which SM you are using ?
> >
> > Also, can you do the following:
> > saquery -g
> > saquery -m
> > and send me the output.
> >
> > I may have some more experiments once I get that level of info.
> >
> > -- Hal
> >   
> We have a Voltaire HW subnet manager. I do not have the saquery command. 
> I'll have to find this and install it.

What is running on your end nodes ? Is it OpenIB/OFED or something else
? If it is OpenIB/OFED, saquery should be there. I think OFED 1.2
supports the options I mentioned.

>  Would the web interface help?

Not sure whether there is anything there for this.

-- Hal

> 
> Sean