Multicast traffic is not going downstream

Unanswered Question
Sep 23rd, 2007

Hi, I am configuring a Multicast Setup , wherein I am sending traffic from IXIA . I am getting mroute entry at CE router but outgoing interface is showing as Null . Bellow are some snapshots . PLease suggest , what could be the problem:


fx-18xx150-ce1-am-atl#sh ip mroute vrf Multi_0


(33.33.33.12, 225.0.0.0), 00:38:50/00:02:46, flags: PT

Incoming interface: FastEthernet0/0.300, RPF nbr 0.0.0.0

Outgoing interface list: Null


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ankbhasi Sun, 09/23/2007 - 22:33

Hi Ashutosh,


Yoru outgoing interface is in prune state as of now. I believe the downstream router has sent a prune message updating that it does not need to join this group.


Need to know more about your setup and which protocol you are running? Is the downstream router the router beyond which end hosts exist?


Regards,


Ankur

ashutosh_pateriya Sun, 09/23/2007 - 22:39

Hi Ankur,

Thanks for ur reply.

Well I have the setup where I have multicast source ( IXIA )connecetd to one CE and one multicast receiver ( IXIA) connected to other CE . I am running PIM-SSM at core and using sparse mode at interfaces . At receiver CE I am getting mrouter entry properly( plz see bellow ):

72xx167vxr#sh ip mroute vrf Multi_0 33.33.33.12 225.0.0.0

IP Multicast Routing Table

Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,

L - Local, P - Pruned, R - RP-bit set, F - Register flag,

T - SPT-bit set, J - Join SPT, M - MSDP created entry,

X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,

U - URD, I - Received Source Specific Host Report,

Z - Multicast Tunnel, z - MDT-data group sender,

Y - Joined MDT-data group, y - Sending to MDT-data group

Outgoing interface flags: H - Hardware switched, A - Assert winner

Timers: Uptime/Expires

Interface state: Interface, Next-Hop or VCD, State/Mode


(*, 225.0.0.0), 2d18h/stopped, RP 212.31.217.117, flags: SJC

Incoming interface: Null, RPF nbr 0.0.0.0

Outgoing interface list:

GigabitEthernet0/1.300, Forward/Sparse, 2d18h/00:02:57

POS1/1.300, Forward/Sparse, 2d18h/00:02:57


Please suggest.


Regds,

Ashutosh

ankbhasi Sun, 09/23/2007 - 23:28

Hi Ashutosh,


Your receiver CE still does not show incoming interface and RPF nbr is 0.0.0.0 and your sender CE does not have any outgoing interface listed. So looks to be some commuication problem between 2 CEs. How are they connected?


Is it possible for you to post the config for 2 CEs.


Regards,


Ankur

ashutosh_pateriya Mon, 09/24/2007 - 04:05

Hi Ankur ,

Both the CEs are configured in static rp mode ( self loopback ip ).


I am sending the config of both the CEs.


Please find the attached file .


Regds,

Ashutosh



Attachment: 
Pavel Bykov Mon, 09/24/2007 - 03:04

Do you have RP's configured correctly for your mode of operation? Are you using only SSM? And if you are using SSM, are you using correct group numbers for the SSM (SSM have a specific address scope dedicated to them).


As per RFC 4601:

" The range of multicast addresses from 232.0.0.0 to 232.255.255.255 is

currently set aside for source-specific multicast in IPv4. For

groups in this range, receivers should only issue source-specific

IGMPv3 joins. If a PIM router receives a non-source-specific join

for a group in this range, it should ignore it, as described in

Section 4.8."


So if you are using SSM and a group of 225.0.0.0, this could be a problem.

Try using 232.0.0.0 instead

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