All things related to multicast

Hi,

I think there are two possibilities too, but not the same as yours
as I didn't considered the fact that there could be multiple multicast
routers on the LAN. So here are the possibilties that I consider :

1) The DR stay on the shared tree toward the RP, even if it receives
an INCLUDE{S} report on an interface, because the flow coming from
S travels already within the shared Tree, so no Join (S,G,spt) is
triggered and no prune(S,G,rpt) too.

2) The DR decide to switch toward S, even if it already has an EXCLUDE{}
   state on it's interface, and prune the shared tree. I see here
   potentials duplicates and lost of paquets, but this is another
   story...

This raises another question : as in ASM and PIM-SM without source
filtering/selection it was clear that the switch toward the RSPT was
controlled and maintained by the DR's, now if the multicast hosts can
decide if they stay on the shared/RSPT tree (possibilities 1), when a host
has switched toward the RSPT, how does it know that this source is not
active anymore apart from the fact that this information may be present in
higher layer protocols (RCTP/SIP) ?

Thanks,

Hoerdt Mickael
LSIIT Laboratory Strasbourg France

On Mon, 24 Nov 2003, bharat_joshi wrote:

> Hi,
>
> If I understand your question correctly, There could be
> two possibilities:
>
> 1) The DR of the LAN will take care of the hosts connected to
> the LAN. Lets say the router which has its interface is in
> EXCULDE {} mode is also the DR of the LAN than this router
> will still send EXCLUDE{} to upstream router i.e. a *,G PIM
> join towards the RP tree and another S,G join towards the
> source. This S,G join will also trigger a S,G,Rpt prune towards
> RP.
>
> 2) If another router is the DR of the LAN, than that router will
> send a S,G join towards the source and also this router who has
> EXCLUDE{} state, will send a *,G towards RP.
>
> I hope this answer your question.
>
> Thanks & Regards,
> Bharat
>
>
> -----Original Message-----
> From: 
> 
>  
> [mailto:]
> Sent: Mon 11/24/2003 4:10 PM
> To:   
> ;
>  
> ;
>  
> 
> Cc:
> Subject:      Question about Multicast Filtering (MLDv2/IGMPv3)
>
> Hello,
>
> I would like to know if someone knows what exactly happens when the
> interface of a multicast router is in EXCLUDE{} state on a LAN and some
> host on the same LAN is in INCLUDE{S} state. Does the multicast router
> stay on the shared tree toward the RP or does it construct a RSPT towards
> S ? It is not clear for me in the draft "igmpv3 and routing protocols
> interaction" if this case is specified.
>
> Thanks,
>
> Hoerdt Mickael
> LSIIT Laboratory - Strasbourg France
>
>
>
>