Re: Multicast Graft and Prune Override

Kid,
routers running PIM-DM to receive a previously pruned (S,G).

-Carlos

CCIE KID @ 21/11/2011 15:18 -0300 dixit:
> Hi Carlos,
>
> Thanks for the info. One more thing who send this graft message and for
> what reason they use this GRAFT message?
>
>
> On Mon, Nov 21, 2011 at 11:41 PM, Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>> wrote:
>
> The problem is not determining the destination ADDRESS of the GRAFT, but
> the INTERFACE you use to send it. You need to send it on RPF(S), but
> if you don't know S, then there's no way to know RPF(S).
> (And don't you dare think of flooding it :)
>
> GRAFT is part of PIM-DM. Hosts have no business in this mantra.
>
> -Carlos
>
> CCIE KID @ 21/11/2011 14:55 -0300 dixit:
>
> Hi Carlos,
>
> U got my question right. What is the destination IP address for
> Graft message. I thought it is 224.0.0.2 --All ROuters address
> and i didnt thought about the Server Source address .. So when
> Flooding happens, the FHR router will flood it to all hosts and
> hosts catch hold of that flood and then they can send a IGMP
> join towards FHR right. Instead of that why does it send GRAFT
> message?
> And wat is the use of Graft message?
>
> On Mon, Nov 21, 2011 at 11:16 PM, Carlos G Mendioroz
> <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>> wrote:
>
> Kid,
> you asked why is there flooding if you could use GRAFT instead.
> (at least that was my interpretation of your Q1).
>
> My answer is that for you to be able to send a GRAFT, you need to
> know where to send it to, but you learn that because of flooding.
> If there were no flooding, the router would never learn the
> sources
> of different groups, so you would not know where to GRAFT to.
>
> BTW, the "client" message is GRAFT, no GRAFT ACK. GRAFT ACK
> is sent
> back to acknowledge reception by the upstream router.
>
> -Carlos
>
> CCIE KID @ 21/11/2011 14:32 -0300 dixit:
>
> hi carlos,
>
> not able to get u man in the first answer. Wat is the use of
> graft and graft ack message. could u elaborate man
>
> On Mon, Nov 21, 2011 at 7:34 PM, Carlos G Mendioroz
> <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>>> wrote:
>
> Kid,
>
> 1) you don't know S before you ever receive a mcast
> packet.
> So you
> can not tell who to send a graft (no RPF interface).
>
> 2) sounds good to me. Two receivers on the same
> segment and one
> decides to PRUNE makes the other shout (JOIN) not to be
> forgotten :)
>
> -Carlos
>
> CCIE KID @ 21/11/2011 08:21 -0300 dixit:
>
> Hi fellas,
>
> I was reading my Multicast theory and i have few
> doubts
> with the
> Dense
> mode.
>
> 1)There is a Graft Ack message sent by the client
> to rejoin a
> particular
> group , ( becasue already he is a member and then
> pruned and
> then again
> joining ) , . At this point the First hop router
> should send
> just a Graft
> Ack message to rejoin the group. If there is Graft
> concept. Why
> there is
> the concept of Flooding n Pruning for every 3
> minutes??
>
> Because Graft Ack just solves the purpose of
> joining again
> instead of
> waiting for 3 minutes for the FHR to send the feed
> again.
> Can some explain me the use of Graft message and
> Graft Ack in
> Multicast
>
>
> 2)Regarding Prune Override .. If there are more
> than two
> routers
> say R1 and
> R2 in a LAN domain. R3 is used as as the FHR
> towards the
> RP Now
> if a host
> connected to R1 is sending a IGMP Leave message
> and now
> R1 sends
> a Group
> specific query and if there is no host which
> replies to this
> query, now
> then R1 will send a PIM prune message to 224.0.0.2
> and now R2
> receives it
> and now it see that there is a host which is actively
> participating in that
> group and it sends a Prune override to R3 and now R3
> still sends
> traffic on
> the link.
>
> Correct me if i am wrong in the above statement.
> Can some one
> explain my
> understanding is correct or not.
>
> R3------------------| Sw1
> |---------------R1--------Host 1
> |
> |
> |
> R2
> |
> |
> |
> Host 2
> This is my scenario
>
>
> With Warmest Regards,
>
> CCIE KID
> CCIE#29992 (Security)
>
>
> Blogs and organic groups at http://www.ccie.net
>
>
> ___________________________________________________________________________________
>
>
> Subscription information may be found at:
> http://www.groupstudy.com/______list/CCIELab.html
> <http://www.groupstudy.com/____list/CCIELab.html>
> <http://www.groupstudy.com/____list/CCIELab.html
> <http://www.groupstudy.com/__list/CCIELab.html>>
>
> <http://www.groupstudy.com/____list/CCIELab.html
> <http://www.groupstudy.com/__list/CCIELab.html>
> <http://www.groupstudy.com/__list/CCIELab.html
> <http://www.groupstudy.com/list/CCIELab.html>>>
>
>
>
>
>
>
>
>
> -- Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>
>
> <mailto:tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>>>
>
> LW7 EQI Argentina
>
>
>
>
> -- With Warmest Regards,
>
> CCIE KID
> CCIE#29992 (Security)
>
>
>
> -- Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar> <mailto:tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>>>
> LW7 EQI Argentina
>
>
>
>
> --
> With Warmest Regards,
>
> CCIE KID
> CCIE#29992 (Security)
>
>
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>
> LW7 EQI Argentina
>
>
>
>
> --
> With Warmest Regards,
>
> CCIE KID
> CCIE#29992 (Security)
>
>

-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net