Subject: [pim] doubt regard RP absence in the network

From: "[email-masked]" <[email-masked]>
Date: Tue, 17 Dec 2002 09:28:00 -0500 (EST)

Hi,
I have the following doubt,

If there is no RP in the network or all the RPs expire in the network. Can there be packet forwarding activity in a PIM-SM (only) domain. In clear my doubt is can the receivers switched over to the packet forwarding via SPT still continue to receive the data packets even if there is not RP information with him.
thanks in advance
rajesh,

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From: Rajamanickam jaganbabu <[email-masked]>
Date: Tue, 17 Dec 2002 15:08:07 +0000 (GMT)

Hi rajesh,
  If the receiver and the source has the Source Path Tree established (i.e if we have (S,G) entry in the Multicast forwarding table), then irrespective of the RP information availability, the multicast packet will be forwarded.
  I hope the above information will help you, if i have understood your question correctly.
Regards,
Jags
 "[email-masked]" <[email-masked]> wrote:Hi,
I have the following doubt,

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From: "Uma C" <[email-masked]>
Date: Tue, 17 Dec 2002 21:48:17 +0530

Hello Jags

When there is no RP information -
1. (*,G) entry would surely get deleted. Outgoing interface in that (*,G)
and (S,G) also gets deleted. So how are the packets still flowing ?
2. If the (*,G) entry alone gets deleted because of the RP information not
present and when the receiver leave the group, will the (S,G) entry get
deleted ?. If yes how ? On what basis will this (S,G) entry get deleted.
I guess the entries at SPT built routers would get deleted only when source
of the multicast packet stops sending packets.

I feel that, when the (*,G) entry gets deleted, (S,G) entry also would be
deleted and there want be a case in which multicast packets will be flowing.
Well I haven't thought about SSM case.

Pl correct me if I am in wrong in my understanding.

Thanks & Regards
C.Uma

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On
Behalf Of Rajamanickam jaganbabu
  Sent: Tuesday, December 17, 2002 8:38 PM
  To: [email-masked]; [email-masked]
  Subject: Re: [pim] doubt regard RP absence in the network

  Hi rajesh,

    If the receiver and the source has the Source Path Tree established (i.e
if we have (S,G) entry in the Multicast forwarding table), then irrespective
of the RP information availability, the multicast packet will be forwarded.

    I hope the above information will help you, if i have understood your
question correctly.

  Regards,

  Jags

   "[email-masked]" <[email-masked]> wrote:

    Hi,

    If there is no RP in the network or all the RPs expire in the network.
Can there be packet forwarding activity in a PIM-SM (only) domain. In clear
my doubt is can the receivers switched over to the packet forwarding via SPT
still continue to receive the data packets even if there is not RP
information with him.
    thanks in advance
    rajesh,

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From: Rajamanickam jaganbabu <[email-masked]>
Date: Wed, 18 Dec 2002 05:45:43 +0000 (GMT)

Hi Uma, 

If there is an IGMPV3 request from the receiver, asking for (S,G,I) join to a particular source, then we will be having an (S,G) entry, which will be the super set of (*,G) outgoing list. If we lost (*,G) information, then it will affect (S,G) inherited outgoing list but there is a possible case where we can have immediate outgoing list exist for (S,G) (which is not in inherited outgoing list), so at this point even we delete (*,G) entry from our multicast forwarding table still (S,G) entry will be existing in the multicast forwarding table.

So my conclusion is, in the above case even if we lost our RP information, still we can forward the multicast packet using (S,G) information for a source "S". 

Thanx, 

Jags

 Uma C <[email-masked]> wrote:Hello Jags When there is no RP information -1. (*,G) entry would surely get deleted. Outgoing interface in that (*,G) and (S,G) also gets deleted. So how are the packets still flowing ?2. If the (*,G) entry alone gets deleted because of the RP information not present and when the receiver leave the group, will the (S,G) entry get deleted ?. If yes how ? On what basis will this (S,G) entry get deleted.I guess the entries at SPT built routers would get deleted only when source of the multicast packet stops sending packets. I feel that, when the (*,G) entry gets deleted, (S,G) entry also would be deleted and there want be a case in which multicast packets will be flowing. Well I haven't thought about SSM case. Pl correct me if I am in wrong in my understanding. Thanks & RegardsC.Uma -----Original Message-----
From: [email-masked] [mailto:[email-masked]]On Behalf Of Rajamanickam jaganbabu
Sent: Tuesday, December 17, 2002 8:38 PM
To: [email-masked]; [email-masked]
Subject: Re: [pim] doubt regard RP absence in the network

Hi rajesh, 
  If the receiver and the source has the Source Path Tree established (i.e if we have (S,G) entry in the Multicast forwarding table), then irrespective of the RP information availability, the multicast packet will be forwarded. 
  I hope the above information will help you, if i have understood your question correctly. 
Regards, 
Jags 
 "[email-masked]" <[email-masked]> wrote: Hi,
I have the following doubt,

---

From: "Uma C" <[email-masked]>
Date: Wed, 18 Dec 2002 12:40:59 +0530

Hello Jags

I guess in the case of IGMPv3, we do not create any (*,G) entry as the Group
range for SSM is different. And as you said we can still forward the packets
whether there is RP information or not.

But in the case of SM only, where (*,G) and (S,G) entry exists and (S,G)
entry holds the oif of the (*,G), if the RP information is not present  -
* (*,G) will be deleted and oif learnt from (*,G) will be deleted from (S,G)
also, irrespective of whether local receivers present or not.
* When the RP information is learnt again, (*,G) entry would be re-created
if the receivers are still present.

Do you still think if RP information is not present (in the case of SM
only), multicast packets would flow ?

Thanks & Regards
C.Uma

  -----Original Message-----
  From: Rajamanickam jaganbabu [mailto:[email-masked]]
  Sent: Wednesday, December 18, 2002 11:16 AM
  To: [email-masked]
  Cc: [email-masked]; [email-masked]
  Subject: RE: [pim] doubt regard RP absence in the network

  Hi Uma,

  If there is an IGMPV3 request from the receiver, asking for (S,G,I) join
to a particular source, then we will be having an (S,G) entry, which will be
the super set of (*,G) outgoing list. If we lost (*,G) information, then it
will affect (S,G) inherited outgoing list but there is a possible case where
we can have immediate outgoing list exist for (S,G) (which is not in
inherited outgoing list), so at this point even we delete (*,G) entry from
our multicast forwarding table still (S,G) entry will be existing in the
multicast forwarding table.

  So my conclusion is, in the above case even if we lost our RP information,
still we can forward the multicast packet using (S,G) information for a
source "S".

  Thanx,

  Jags

   Uma C <[email-masked]> wrote:

    Hello Jags

    When there is no RP information -
    1. (*,G) entry would surely get deleted. Outgoing interface in that
(*,G) and (S,G) also gets deleted. So how are the packets still flowing ?
    2. If the (*,G) entry alone gets deleted because of the RP information
not present and when the receiver leave the group, will the (S,G) entry get
deleted ?. If yes how ? On what basis will this (S,G) entry get deleted.
    I guess the entries at SPT built routers would get deleted only when
source of the multicast packet stops sending packets.

    I feel that, when the (*,G) entry gets deleted, (S,G) entry also would
be deleted and there want be a case in which multicast packets will be
flowing. Well I haven't thought about SSM case.

    Thanks & Regards
    C.Uma

      -----Original Message-----

      Hi rajesh,

        If the receiver and the source has the Source Path Tree established
(i.e if we have (S,G) entry in the Multicast forwarding table), then
irrespective of the RP information availability, the multicast packet will
be forwarded.

        I hope the above information will help you, if i have understood
your question correctly.

      Regards,

      Jags

        Hi,

        If there is no RP in the network or all the RPs expire in the
network. Can there be packet forwarding activity in a PIM-SM (only) domain.
In clear my doubt is can the receivers switched over to the packet
forwarding via SPT still continue to receive the data packets even if there
is not RP information with him.
        thanks in advance
        rajesh,

------------------------------------------------------------------------
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       Catch all the cricket action. Download Yahoo! Score tracker